This is the accessible text file for GAO report number GAO-07-86 
entitled 'Medicare: Payment for Ambulatory Surgical Centers Should Be 
Based on the Hospital Outpatient Payment System' which was released on 
November 30, 2006. 

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Report to Congressional Committees: 

United States Government Accountability Office: 

GAO: 

November 2006: 

Medicare: 

Payment for Ambulatory Surgical Centers Should Be Based on the Hospital 
Outpatient Payment System: 

Medicare Payment for Ambulatory Surgical Centers: 

GAO-07-86: 

GAO Highlights: 

Highlights of GAO-07-86, a report to congressional committees 

Why GAO Did This Study: 

Medicare pays for surgical procedures performed at ambulatory surgical 
centers (ASC) and hospital outpatient departments through different 
payment systems. Although they perform a similar set of procedures, no 
comparison of ASC and hospital outpatient per-procedure costs has been 
conducted. The Medicare Prescription Drug, Improvement, and 
Modernization Act of 2003 directed GAO to compare the relative costs of 
procedures furnished in ASCs to the relative costs of those procedures 
furnished in hospital outpatient departments, in particular, how 
accurately the payment groups used in the hospital outpatient 
prospective payment system (OPPS) reflect the relative costs of 
procedures performed in ASCs. To do this, GAO collected data from ASCs 
through a survey. GAO also obtained hospital outpatient data from the 
Centers for Medicare & Medicaid Services (CMS). 

What GAO Found: 

GAO determined that the payment groups in the OPPS, known as ambulatory 
payment classification (APC) groups, accurately reflect the relative 
cost of procedures performed in ASCs. GAO calculated the ratio between 
each procedure’s ASC median cost, as determined by GAO’s survey, and 
the median cost of each procedure’s corresponding APC group under the 
OPPS, referred to as the ASC-to-APC cost ratio. GAO also compared the 
OPPS median costs of those same procedures with the median costs of 
their APC groups, referred to as the OPPS-to-APC cost ratio. GAO’s 
analysis of the ASC-to-APC and OPPS-to-APC cost ratios showed that 45 
percent of all procedures in the analysis fell within a 0.10 point 
range of the ASC-to-APC median cost ratio, and 33 percent of procedures 
fell within a 0.10 point range of the OPPS-to-APC median cost ratio. 
These similar patterns of distribution around the median show that the 
APC groups reflect the relative costs of procedures provided by ASCs as 
well as they reflect the relative costs of procedures provided in 
hospital outpatient departments and can be used as the basis for the 
ASC payment system. GAO’s analysis also identified differences in the 
cost of procedures in the two settings. The median cost ratio among all 
ASC procedures was 0.39 and when weighted by Medicare claims volume was 
0.84. The median cost ratio for OPPS procedures was 1.04. Thus, the 
cost of procedures in ASCs is substantially lower than the 
corresponding cost in hospital outpatient departments. 

Figure: ASC Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

[See PDF for Image] 

Source: GAO analysis of ASC survey and Medicare data. 

[End of Figure] 

Figure: OPPS Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

[See PDF for Image] 

Source: GAO analysis of Medicare data. 

[End of Figure] 

What GAO Recommends: 

The Administrator of CMS should implement a payment system for 
procedures performed in ASCs based on the OPPS, taking into account the 
lower relative costs of procedures performed in ASCs compared to 
hospital outpatient departments. CMS stated that GAO’s recommendation 
is consistent with its August 2006 proposed revisions to the ASC 
payment system. 

[Hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-07-86]. 

To view the full product, including the scope and methodology, click on 
the link above. For more information, contact Kathleen King at (202) 
512-7119 or kingk@gao.gov. 

[End of Section] 

Contents: 

Letter: 

Background: 

Results in Brief: 

Many Additional Billed Services Were Similar; Few Resulted in 
Additional Payments to ASCs or Hospital Outpatient Departments: 

APC Groups Accurately Reflect ASC Procedure Costs: 

Conclusions: 

Recommendation for Executive Action: 

Agency and External Reviewer Comments and Our Evaluation: 

Appendix I: Analysis of the Proportion of Labor-Related Costs for 
Ambulatory Surgical Centers: 

Appendix II: Scope and Methodology: 

Appendix III: Additional Procedures Billed with the Top 20 ASC 
Procedures, 2003: 

Appendix IV: Comments from the Centers for Medicare & Medicaid 
Services: 

Appendix V: GAO Contact and Staff Acknowledgments: 

Figures: 

Figure 1: ASC Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

Figure 2: OPPS Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

Figure 3: ASC Per-Procedure Cost Calculations from ASC Survey: 

Abbreviations: 

AAASC: American Association of Ambulatory Surgery Centers: 
APC: ambulatory payment classification: 
ASC: ambulatory surgical center: 
CMS: Centers for Medicare & Medicaid Services: 
GI: gastrointestinal: 
MMA: Medicare Prescription Drug, Improvement, and Modernization Act of 
2003: 
NCH: National Claims History: 
ORA: Omnibus Reconciliation Act of 1980: 
OPPS: outpatient prospective payment system: 

United States Government Accountability Office: 
Washington, DC 20548: 

November 30, 2006: 

The Honorable Charles E. Grassley: 
Chairman: 
The Honorable Max Baucus: 
Ranking Minority Member: 
Committee on Finance: 
United States Senate: 

The Honorable Joe Barton: 
Chairman: 
The Honorable John D. Dingell: 
Ranking Minority Member: 
Committee on Energy and Commerce: 
House of Representatives: 

The Honorable William M. Thomas: 
Chairman: 
The Honorable Charles B. Rangel: 
Ranking Minority Member: 
Committee on Ways and Means: 
House of Representatives: 

In 1982, Medicare began paying ambulatory surgical centers (ASC) to 
perform certain surgical procedures on an outpatient basis. ASCs were 
established as an alternative to hospital inpatient care, which was 
considered a more costly setting. Medicare's initial ASC payment rates 
were based on ASC cost and charge data from 1979 and 1980. The Centers 
for Medicare & Medicaid Services (CMS), the agency that administers 
Medicare, was required by law to review the ASC payment rates 
periodically and adjust them as appropriate.[Footnote 1] CMS last 
revised the ASC payment rates in 1990 using ASC data on costs and 
charges that CMS collected in 1986.[Footnote 2] Since the payment rates 
were last revised, there has been substantial growth in both the number 
of ASC facilities and procedures they perform, as well as changes in 
medical practice and technology. In 2004, there were approximately 
4,100 Medicare-participating ASCs, a number that has grown 
substantially since 2000 when there were about 2,900 Medicare- 
participating ASCs. In 2004, ASCs received approximately $2.5 billion 
in total Medicare payments, a 79 percent increase since 2000 when 
Medicare payments to ASCs totaled approximately $1.4 billion. 

While the ASC setting was originally intended to be an alternative to 
hospital inpatient care, the procedures performed in ASCs are now 
frequently performed in the hospital outpatient setting. Medicare pays 
ASCs and hospital outpatient departments through different payment 
systems. While procedures performed in ASCs are placed into payment 
groups based on similar costs, hospital outpatient department 
procedures are placed into payment groups, known as ambulatory payment 
classification (APC) groups, based on both cost and clinical 
similarity. Unlike the ASC payment system, the payment rates for 
hospital outpatient departments are revised annually based on cost and 
charge data included in reports hospitals are required to submit to CMS 
each year. 

Although ASCs and hospital outpatient departments perform a similar set 
of procedures, no comparison between the Medicare ASC payment system 
and the Medicare hospital outpatient department payment system, known 
as the outpatient prospective payment system (OPPS), has been 
conducted. The Medicare Prescription Drug, Improvement, and 
Modernization Act of 2003 (MMA) directed us to conduct a study that 
compares the relative costs of procedures performed in ASCs to the 
relative costs of procedures performed in hospital outpatient 
departments.[Footnote 3] As discussed with the committees of 
jurisdiction, we compared (1) additional services billed with 
procedures performed in ASCs with those billed with procedures 
performed in hospital outpatient departments and whether there were any 
Medicare payments associated with those services and (2) the relative 
costs of procedures when performed in ASCs to the relative costs of 
those procedures when performed in hospital outpatient departments, in 
particular, how accurately the APC groups used in the OPPS reflect the 
relative costs of procedures performed in the ASC setting. In addition, 
we examined the proportion of ASCs' costs that are labor-related; this 
information is provided in appendix I. 

To compare the delivery of additional services provided with procedures 
performed in ASCs and hospital outpatient departments, we identified 
all additional services frequently provided in each setting with one of 
the top 20 procedures based on highest Medicare ASC claims 
volume,[Footnote 4] which, as a group, represented approximately 75 
percent of all Medicare ASC claims volume in 2003.[Footnote 5] Using 
Medicare claims data for 2003, we identified beneficiaries receiving 
one of the top 20 procedures performed in either an ASC or hospital 
outpatient department, then identified any other claims for those 
beneficiaries submitted by ASCs, hospital outpatient departments, 
durable medical equipment suppliers, and other Medicare part B 
providers. We identified claims for the beneficiaries on the day the 
procedure was performed and the day after.[Footnote 6] We created a 
list that included all additional services that were billed at least 10 
percent of the time with each of the top 20 procedures when they were 
performed in ASCs. We created a similar list of additional services for 
each of the top 20 procedures when they were performed in hospital 
outpatient departments. We then compared the lists to determine if the 
additional services provided by ASCs and hospital outpatient 
departments with each of those procedures were similar. To compare the 
Medicare payments for additional services provided with procedures 
performed in ASCs and hospital outpatient departments, we identified 
whether any additional services included in our analysis resulted in an 
additional payment. 

To compare the costs of procedures performed in ASCs and hospital 
outpatient departments, we first compiled information on ASCs' costs 
and procedures performed. We conducted a survey of 600 ASCs to obtain 
2004 cost and procedure data. We received responses from 397 ASC 
facilities, and through our data reliability testing, determined that 
data from 290 responding facilities were sufficiently reliable for our 
purposes. 

To allocate ASCs' costs among the individual procedures they perform, 
we first separated ASCs' direct and indirect costs. We then allocated 
each ASC's direct costs among procedures it performed using a relative 
weight scale we constructed with data from CMS, supplemented by 
information from medical specialty societies and clinicians who work 
for CMS. The relative weight scale captures the general variation in 
costs associated with performing the different procedures. We allocated 
each ASC's indirect costs equally across all procedures it performed. 
For each procedure, we summed the direct and indirect costs for each 
ASC and arrayed the total cost for each of the ASCs performing that 
procedure. To obtain a per-procedure cost across all ASCs, we then 
identified the median cost for each procedure from the array. 

To compare per-procedure costs for ASCs and hospital outpatient 
departments, we first obtained from CMS the list of APC groups included 
in the OPPS and the procedures assigned to each APC group. We also 
obtained from CMS the OPPS median cost of each procedure and the median 
cost of each APC group. We then calculated a ratio between the median 
cost for each procedure performed at an ASC, as determined by the 
survey, and the median cost of each procedure's corresponding APC group 
under the OPPS. For the same procedures, we also calculated a ratio 
between the median cost of each procedure under the OPPS and the median 
cost of the procedure's APC group, using the data obtained from CMS. To 
evaluate the difference in procedure costs between the two settings, we 
compared the ASC-to-APC and OPPS-to-APC cost ratios. To assess how well 
the relative costs of procedures in the OPPS, defined by their 
assignment to APC groups, reflect the relative costs of procedures in 
the ASC setting, we evaluated the distribution of the ASC-to-APC and 
OPPS-to-APC cost ratios. 

We also conducted interviews with CMS officials and representatives 
from ASC industry organizations, specifically, the American Association 
of Ambulatory Surgery Centers (AAASC) and FASA, as well as physician 
specialty societies, and individual ASCs. For details on our methods, 
see appendix II. We performed our work from April 2004 through October 
2006 in accordance with generally accepted government auditing 
standards. 

Background: 

There are some similarities in how Medicare pays ASCs and hospital 
outpatient departments for the procedures they perform. However, the 
methods used by CMS to calculate the payment rates in each system, as 
well as the mechanisms used to revise the Medicare payment rates, 
differ. 

Structure of the ASC Payment System: 

In 1980, legislation was enacted that enabled ASCs to bill Medicare for 
certain surgical procedures provided to Medicare 
beneficiaries.[Footnote 7] Under the ASC payment system, Medicare pays 
a predetermined, and generally all-inclusive, amount per procedure to 
the facility. The approximately 2,500 surgical procedures that ASCs may 
bill for under Medicare are assigned to one of nine payment groups that 
contain procedures with similar costs, but not necessarily clinical 
similarities. All procedures assigned to one payment group are paid at 
the same rate. Under the Medicare payment system, when more than one 
procedure is performed at the same time, the ASC receives a payment for 
each of the procedures. However, the procedure that has the highest 
payment rate receives 100 percent of the applicable payment, and each 
additional procedure receives 50 percent of the applicable payment. 

The Medicare payment for a procedure performed at an ASC is intended to 
cover the direct costs for a procedure, such as nursing and technician 
services, drugs, medical and surgical supplies and equipment, 
anesthesia materials, and diagnostic services (including imaging 
services), and the indirect costs associated with the procedure, 
including use of the facility and related administrative services. The 
ASC payment for a procedure does not include payment for implantable 
devices or prosthetics related to the procedure; ASCs may bill 
separately for those items. In addition, the payment to the ASC does 
not include payment for professional services associated with the 
procedure; the physician who performs the procedure and the 
anesthesiologist or anesthetist bill Medicare directly for their 
services. Finally, the ASC payment does not include payment for certain 
other services that are not directly related to performing the 
procedure and do not occur during the time that the procedure takes 
place, such as some laboratory, X-ray, and other diagnostic tests. 
Because these additional services are not ASC procedures, they may be 
performed by another provider. In those cases, Medicare makes payments 
to those providers for the additional services. For example, a 
laboratory service needed to evaluate a tissue sample removed during an 
ASC procedure is not included in the ASC payment. The provider that 
evaluated the tissue sample would bill and receive payment from 
Medicare for that service. Because ASCs receive one inclusive payment 
for the procedure performed and its associated services, such as drugs, 
they generally include on their Medicare claim only the procedure 
performed. 

Structure of the OPPS: 

In 1997, legislation was enacted that required the implementation of a 
prospective payment system for hospital outpatient 
departments;[Footnote 8] the OPPS was implemented in August 2000. 
Although ASCs perform only procedures, hospital outpatient departments 
provide a much broader array of services, including diagnostic 
services, such as X-rays and laboratory tests, and emergency room and 
clinic visits. Each of the approximately 5,500 services, including 
procedures, that hospital outpatient departments perform is assigned to 
one of over 800 APC groups with other services with clinical and cost 
similarities for payment under the OPPS. All services assigned to one 
APC group are paid the same rate. Similar to ASCs, when hospitals 
perform multiple procedures at the same time, they receive 100 percent 
of the applicable payment for the procedure that has the highest 
payment rate, and 50 percent of the applicable payment for each 
additional procedure, subject to certain exceptions. 

Like payments to ASCs, payment for a procedure under the OPPS is 
intended to cover the costs of the use of the facility, nursing and 
technician services, most drugs, medical and surgical supplies and 
equipment, anesthesia materials, and administrative costs. Medicare 
payment to a hospital for a procedure does not include professional 
services for physicians or other nonphysician practitioners. These 
services are paid for separately by Medicare. However, there are some 
differences between ASC and OPPS payments for procedures. Under the 
OPPS, hospital outpatient departments generally may not bill separately 
for implantable devices related to the procedure, but they may bill 
separately for additional services that are directly related to the 
procedure, such as certain drugs and diagnostic services, including X- 
rays.[Footnote 9] Hospital outpatient departments also may bill 
separately for additional services that are not directly related to the 
procedure and do not occur during the procedure, such as laboratory 
services to evaluate a tissue sample. Because they provide a broader 
array of services, and because CMS has encouraged hospitals to report 
all services provided during a procedure on their Medicare claims for 
rate-setting purposes, hospital claims may provide more detail about 
the services delivered during a procedure than ASC claims do. 

History of the ASC System Rate Setting: 

CMS set the initial 1982 ASC payment rates based on cost and charge 
data from 40 ASCs. At that time, there were about 125 ASCs in 
operation. Procedures were placed into four payment groups, and all 
procedures in a group were paid the same rate. When the ASC payment 
system was first established, federal law required CMS to review the 
payment rates periodically.[Footnote 10] In 1986, CMS conducted an ASC 
survey to gather cost and charge data. In 1990, using these data, CMS 
revised the payment rates and increased the number of payment groups to 
eight. A ninth payment group was established in 1991. These groups are 
still in use, although some procedures have been added to or deleted 
from the ASC-approved list. 

Although payments have not been revised using ASC cost data since 1990, 
the payment rates have been periodically updated for inflation. In 
1994, Congress required that CMS conduct a survey of ASC costs no later 
than January 1, 1995, and thereafter every 5 years, to revise ASC 
payment rates.[Footnote 11] CMS conducted a survey in 1994 to collect 
ASC cost data. In 1998, CMS proposed revising ASC payment rates based 
on the 1994 survey data and assigned procedures performed at ASCs into 
payment groups that were comparable to the payment groups it was 
developing for the same procedures under the OPPS.[Footnote 12] 
However, CMS did not implement the proposal, and, as a result, the ASC 
payment system was not revised using the 1994 data. In 2003, MMA 
eliminated the requirement to conduct ASC surveys every 5 years and 
required CMS to implement a revised ASC payment system no later than 
January 1, 2008.[Footnote 13] During the course of our work, in August 
2006, CMS published a proposed rule that would revise the ASC payment 
system effective January 1, 2008.[Footnote 14] In this proposed rule, 
CMS bases the revised ASC payment rates on the OPPS APC groups. 
However, the payment rates would be lower for ASCs. 

History of OPPS Rate Setting: 

The initial OPPS payment rates, implemented in August 2000, were based 
on hospitals' 1996 costs. To determine the OPPS payment rates, CMS 
first calculates each hospital's cost for each service by multiplying 
the charge for that service by a cost-to-charge ratio computed from the 
hospital's most recently reported data.[Footnote 15] After calculating 
the cost of each service for each hospital, the services are grouped by 
their APC assignment, and a median cost for each APC group is 
calculated from the median costs of all services assigned to it. Using 
the median cost, CMS assigns each APC group a weight based on its 
median cost relative to the median cost of all other APCs. To obtain a 
payment rate for each APC group, CMS multiplies the relative weight by 
a factor that converts it to a dollar amount. Beginning in 2002, as 
required by law, the APC group payment rates have been revised annually 
based on the latest charge and cost data.[Footnote 16] In addition, the 
payment rates for services paid under the OPPS receive an annual 
inflation update. 

Results in Brief: 

For the top 20 procedures, we found many similarities in the additional 
services billed with procedures performed by ASCs and hospital 
outpatient departments.[Footnote 17] Of the additional services billed 
in either setting with a top 20 procedure, few are paid separately by 
Medicare in one setting but not the other. Hospital outpatient 
departments received payment for some of the additional services, such 
as X-rays, they billed with the procedures, while in the ASC setting, 
other providers billed Medicare for these services and received payment 
for them. This is a result of the differences in the structure of the 
two payment systems; that is, while ASCs may bill Medicare only for 
procedures, hospitals may bill for a broader array of services. 

The APC groups in the OPPS accurately reflect the relative costs of 
procedures performed at ASCs. We compared each procedure's ASC median 
cost to the median cost of the APC group in which it would be placed, 
which we refer to as the ASC-to-APC cost ratio. We repeated this 
analysis by comparing the costs of those same procedures under the OPPS 
with the median costs of their APC groups, which we refer to as the 
OPPS-to-APC cost ratio. Our analysis of the cost ratios showed that the 
ASC-to-APC cost ratios were more tightly distributed around their 
median cost ratio than were the OPPS-to-APC cost ratios; that is, more 
of them were closer to their respective median. Specifically, 45 
percent of all procedures in our analysis fell within a 0.10 point 
range of the ASC-to-APC median cost ratio, and 33 percent of procedures 
fell within a 0.10 point range of the OPPS-to-APC median cost ratio. 
These similar patterns show that the APC groups reflect the relative 
costs of procedures provided by ASCs as well as they reflect the 
relative costs of procedures provided in the hospital outpatient 
department setting and can be used as the basis for an ASC payment 
system. While our analysis demonstrated that the APC groups accurately 
reflect the relative cost of procedures performed in ASCs, it also 
showed that procedures in the ASC setting had substantially lower costs 
than those same procedures in the hospital outpatient department 
setting. The median cost ratio among all ASC procedures was 0.39. The 
median cost ratio among all OPPS procedures was 1.04. 

We recommend that the Administrator of CMS implement a payment system 
for procedures performed in ASCs based on the OPPS, taking into account 
the lower relative costs of procedures in ASCs compared to hospital 
outpatient departments. In commenting on a draft of this report, CMS 
stated that our recommendation is consistent with its August 2006 
proposed revisions to the ASC payment system. Representatives of AAASC 
and FASA, who reviewed a draft of this report, provided comments, which 
we incorporated where appropriate. 

Many Additional Billed Services Were Similar; Few Resulted in 
Additional Payments to ASCs or Hospital Outpatient Departments: 

We found many similarities in the additional services provided by ASCs 
and hospital outpatient departments with the top 20 procedures. Of the 
additional services billed with a procedure, few resulted in an 
additional payment in one setting but not the other. Hospitals were 
paid for some of the related additional services they billed with the 
procedures. In the ASC setting, other providers billed Medicare for 
these services and received payment for them. 

Many Additional Services Billed in Each Setting Were Similar: 

In our analysis of Medicare claims, we found many similarities in the 
additional services billed in the ASC or hospital outpatient department 
setting with the top 20 procedures. The similar additional services are 
illustrated in the following four categories of services: additional 
procedures, laboratory services, radiology services, and anesthesia 
services. 

First, one or more additional procedures was billed with a procedure 
performed in either the ASC or hospital outpatient department setting 
for 14 of the top 20 procedures. The proportion of time each additional 
procedure was billed in each setting was similar. For example, when a 
hammertoe repair procedure was performed, our analysis indicated that 
another procedure to correct a bunion was billed 11 percent of the time 
in the ASC setting, and in the hospital outpatient setting, the 
procedure to correct a bunion was billed 13 percent of the time. 
Similarly, when a diagnostic colonoscopy was performed, an upper 
gastrointestinal (GI) endoscopy was billed 11 percent of the time in 
the ASC setting, and in the hospital setting, the upper GI endoscopy 
was billed 12 percent of the time. For 11 of these 14 procedures, the 
proportion of time each additional procedure was billed differed by 
less than 10 percentage points between the two settings. For the 3 
remaining procedures, the percentage of time that an additional 
procedure was billed did not vary by more than 25 percentage points 
between the two settings. See appendix III for a complete list of the 
additional procedures billed and the proportion of time they were 
billed in each setting. 

Second, laboratory services were billed with 10 of the top 20 
procedures in the hospital outpatient department setting and 7 of the 
top 20 procedures in the ASC setting. While these services were almost 
always billed by the hospital in the outpatient setting, they were 
typically not billed by the ASCs. These laboratory services were 
present in our analysis in the ASC setting because they were performed 
and billed by another Medicare part B provider. 

Third, four different radiology services were billed with 8 of the top 
20 procedures. Radiology services were billed with 5 procedures in the 
ASC setting and with 8 procedures in the hospital outpatient department 
setting. The radiology services generally were included on the hospital 
outpatient department bills but rarely were included on the ASC bills. 
Similar to laboratory services, hospital outpatient departments billed 
for radiology services that they performed in addition to the 
procedures. When radiology services were billed with procedures in the 
ASC setting, these services generally were performed and billed by 
another part B provider. 

Fourth, anesthesia services were billed with 17 of the top 20 
procedures in either the ASC or hospital outpatient settings and with 
14 procedures in both settings. In virtually every case in the ASC 
setting, and most cases in the hospital outpatient department setting, 
these services were billed by another part B provider. 

According to our analysis, ASCs did not generally include any services 
other than the procedures they performed on their bills. However, in 
the hospital outpatient setting, some additional services were included 
on the hospitals' bills. We believe this is a result of the structure 
of the two payment systems. As ASCs generally receive payment from 
Medicare only for procedures, they typically include only those 
procedures on their bills. In contrast, hospital outpatient 
departments' bills often include many of the individual items or 
services they provide as a part of a procedure because CMS has 
encouraged them to do so, whether the items or services are included in 
the OPPS payment or paid separately. 

Additional Services Resulted in Few Additional Payments to ASCs or 
Hospital Outpatient Departments: 

With the exception of additional procedures, there were few separate 
payments that could be made for additional services provided with the 
top 20 procedures because most of the services in our analysis were 
included in the Medicare payment to the ASC or hospital. Under both the 
Medicare ASC and OPPS payment systems, when more than one procedure is 
performed at the same time, the facility receives 100 percent of the 
applicable payment for the procedure that has the highest payment rate 
and 50 percent of the applicable payment for each additional procedure. 
As this policy is applicable to both settings, for those instances in 
our analysis when an additional procedure was performed with one of the 
top 20 procedures in either setting, the ASC or hospital outpatient 
department received 100 percent of the payment for the procedure with 
the highest payment rate and 50 percent of the payment for each lesser 
paid procedure. 

Individual drugs were billed by hospital outpatient departments for 
most of the top 20 procedures, although they were not present on the 
claims from ASCs, likely because ASCs generally cannot receive separate 
Medicare payments for individual drugs. However, none of the individual 
drugs billed by the hospital outpatient departments in our analysis 
resulted in an additional payment to the hospitals. In each case, the 
cost of the particular drug was included in the Medicare payment for 
the procedure. 

In the case of the laboratory services billed with procedures in the 
ASC and hospital outpatient department settings, those services were 
not costs included in the payment for the procedure in either setting 
and were paid separately in each case. For both settings, the payment 
was made to the provider that performed the service. In the case of the 
hospital outpatient department setting, the payment was generally made 
to the hospital, while, for procedures performed at ASCs, payment was 
made to another provider who performed the service. 

Of the four radiology services in our analysis, three were similar to 
the laboratory services in that they are not included in the cost of 
the procedure and are separately paid services under Medicare. 
Therefore, when hospitals provided these services, they received 
payment for them. In the ASC setting, these services were typically 
billed by a provider other than the ASC, and the provider received 
payment for them. The fourth radiology service is included in the 
payment for the procedure with which it was associated. Therefore, no 
separate payment was made to either ASCs or hospital outpatient 
departments. With regard to anesthesia services, most services were 
billed by and paid to a provider other than an ASC or hospital. 

APC Groups Accurately Reflect ASC Procedure Costs: 

As a group, the costs of procedures performed in ASCs have a relatively 
consistent relationship with the costs of the APC groups to which they 
would be assigned under the OPPS. That is, the APC groups accurately 
reflect the relative costs of procedures performed in ASCs. We found 
that the ASC-to-APC cost ratios were more tightly distributed around 
their median cost ratio than the OPPS-to-APC cost ratios were around 
their median cost ratio. Specifically, 45 percent of all procedures in 
our analysis fell within 0.10 points of the ASC-to-APC median cost 
ratio, and 33 percent of procedures fell within 0.10 points of the OPPS-
to-APC median cost ratio. However, the costs of procedures in ASCs are 
substantially lower than costs for the same procedures in the hospital 
outpatient setting. 

APC Groups Accurately Reflect the Relative Costs of ASC Procedures: 

The APC groups reflect the relative costs of procedures provided by 
ASCs as well as they reflect the relative costs of procedures provided 
in the hospital outpatient department setting. In our analysis, we 
listed the procedures performed at ASCs and calculated the ratio of the 
cost of each procedure to the cost of the APC group to which it would 
have been assigned, referred to as the ASC-to-APC cost ratio. We then 
calculated similar cost ratios for the same procedures exclusively 
within the OPPS. To determine an OPPS-to-APC cost ratio, we divided 
individual procedures' median costs, as calculated by CMS for the OPPS, 
by the median cost of their APC group. Our analysis of the cost ratios 
showed that the ASC-to-APC cost ratios were more tightly distributed 
around their median than were the OPPS-to-APC cost ratios; that is, 
there were more of them closer to the median. Specifically, 45 percent 
of procedures performed in ASCs fell within a 0.10 point range of the 
ASC-to-APC median cost ratio, and 33 percent of those procedures fell 
within a 0.10 point range of the OPPS-to-APC median cost ratio in the 
hospital outpatient department setting (see figs. 1 and 2). Therefore, 
there is less variation in the ASC setting between individual 
procedures' costs and the costs of their assigned APC groups than there 
is in the hospital outpatient department setting. From this outcome, we 
determined that the OPPS APC groups could be used to pay for procedures 
in ASCs. 

Figure 1: ASC Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

[See PDF for image] 

Source: GAO analysis of ASC survey and Medicare data. 

[End of figure] 

Figure 2: OPPS Procedure Median Cost to APC Median Cost Ratios, 
Distributed by Percentage in 0.05 Increments, 2004: 

[See PDF for image] 

Source: GAO analysis of Medicare data. 

[End of figure] 

ASC Procedures' Median Costs Are Generally Lower Than Those for OPPS 
Procedures: 

The median costs of procedures performed in ASCs were generally lower 
than the median costs of their corresponding APC group under the 
OPPS.[Footnote 18] Among all procedures in our analysis, the median ASC-
to-APC cost ratio was 0.39.[Footnote 19] The ASC-to-APC cost ratios 
ranged from 0.02 to 3.34. When weighted by Medicare volume based on 
2004 claims data, the median ASC-to-APC cost ratio was 0.84. We 
determined that the median OPPS-to-APC cost ratio was 1.04. This 
analysis shows that when compared to the median cost of the same APC 
group, procedures performed in ASCs had substantially lower costs than 
when those same procedures were performed in hospital outpatient 
departments. 

Conclusions: 

Generally, there are many similarities between the additional services 
provided in ASCs and hospital outpatient departments with one of the 
top 20 procedures, and few resulted in an additional Medicare payment 
to ASCs or hospital outpatient departments. Although costs for 
individual procedures vary, in general, the median costs for procedures 
are lower in ASCs, relative to the median costs of their APC groups, 
than the median costs for the same procedures in the hospital 
outpatient department setting. The APC groups in the OPPS reflect the 
relative costs of procedures performed in ASCs in the same way that 
they reflect the relative costs of the same procedures when they are 
performed in hospital outpatient departments. Therefore, the APC groups 
could be applied to procedures performed in ASCs, and the OPPS could be 
used as the basis for an ASC payment system, eliminating the need for 
ASC surveys and providing for an annual revision of the ASC payment 
groups. 

Recommendation for Executive Action: 

We recommend that the Administrator of CMS implement a payment system 
for procedures performed in ASCs based on the OPPS. The Administrator 
should take into account the lower relative costs of procedures 
performed in ASCs compared to hospital outpatient departments in 
determining ASC payment rates. 

Agency and External Reviewer Comments and Our Evaluation: 

We received written comments on a draft of this report from CMS (see 
app. IV). We also received oral comments from external reviewers 
representing two ASC industry organizations, AAASC and FASA. 

CMS Comments: 

In commenting on a draft of this report, CMS stated that our 
recommendation is consistent with its August 2006 proposed revisions to 
the ASC payment system. 

Industry Comments and Our Evaluation: 

Industry representatives who reviewed a draft of this report did not 
agree or disagree with our recommendation for executive action. They 
did, however, provide several comments on the draft report. The 
industry representatives noted that we did not analyze the survey 
results to examine differences in per-procedure costs among single- 
specialty and multi-specialty ASCs. Regarding this comment, we 
initially considered developing our survey sample stratified by ASC 
specialty type. However, because accurate data identifying ASCs' 
specialties do not exist, we were unable to stratify our survey sample 
by specialty type. 

The industry representatives asked us to provide more explanation in 
our scope and methodology regarding our development of a relative 
weight scale for Medicare ASC-approved procedures to capture the 
general variation in resources associated with performing different 
procedures. We expanded the discussion of how we developed the relative 
weight scale in our methodology section. 

Reviewers also made technical comments, which we incorporated where 
appropriate. 

We are sending a copy of this report to the Administrator of CMS and 
appropriate congressional committees. The report is available at no 
charge on GAO's Web site at [Hyperlink, http://www.gao.gov]. We will 
also make copies available to others on request. 

If you or your staff members have any questions about this report, 
please contact me at (202) 512-7119 or kingk@gao.gov. Contact points 
for our Offices of Congressional Relations and Public Affairs may be 
found on the last page of this report. GAO staff members who made 
significant contributions to this report are listed in appendix V. 

Signed by: 

Kathleen King: 
Director, Health Care: 

[End of section] 

Appendix I: Analysis of the Proportion of Labor-Related Costs for 
Ambulatory Surgical Centers: 

The Medicare payment rates for ambulatory surgical centers (ASC), along 
with those of other facilities, are adjusted to account for the 
variation in labor costs across the country. To calculate payment rates 
for individual ASCs, the Centers for Medicare & Medicaid Services (CMS) 
calculates the share of total costs that are labor-related and then 
adjusts ASCs' labor-related share of costs based on a wage index 
calculated for specific geographic areas across the country. The wage 
index reflects how the average wage for health care personnel in each 
geographic area compares to the national average health care personnel 
wage. The geographic areas are intended to represent the separate labor 
markets in which health care facilities compete for employees. 

In setting the initial ASC payment rates for 1982, CMS determined from 
the first survey of ASCs that one-third of their costs were labor- 
related. The labor-related costs included employee salaries and fringe 
benefits, contractual personnel, and owners' compensation for duties 
performed for the facility. To determine the payment rates for each 
individual ASC, CMS multiplied one-third of the payment rate for each 
procedure--the labor-related portion--by the local area wage index. 
Each ASC received the base payment rate for two-thirds of the payment 
rate--the nonlabor-related portion--for each procedure. The sum of the 
labor-related and nonlabor-related portions equaled each ASC's payment 
rate for each procedure. 

In 1990, when CMS revised the payment system based on a 1986 ASC 
survey, CMS found ASCs' average labor-related share of costs to be 
34.45 percent and used this percentage as the labor-related portion of 
the payment rate. In a 1998 proposed rule, CMS noted that ASCs' share 
of labor-related costs as calculated from the 1994 ASC cost survey had 
increased to an average of 37.66 percent, slightly higher than the 
percentage calculated from the 1986 survey. However, CMS did not 
implement the 1998 proposal. Currently, the labor-related proportion of 
costs from CMS's 1986 survey, 34.45 percent, is used for calculating 
ASC payment rates. 

Using 2004 cost data we received from 290 ASCs that responded to our 
survey request for information, we determined that the mean labor- 
related proportion of costs was 50 percent, and the range of the labor- 
related costs for the middle 50 percent of our ASC facilities was 43 
percent to 57 percent of total costs. 

[End of section] 

Appendix II: Scope and Methodology: 

To compare the delivery of procedures between ASCs and hospital 
outpatient departments, we analyzed Medicare claims data from 2003. To 
compare the relative costs of procedures performed in ASCs and hospital 
outpatient departments, we collected cost and procedure data from 2004 
from a sample of Medicare-participating ASCs. We also interviewed 
officials at CMS and representatives from ASC industry organizations, 
specifically, the American Association of Ambulatory Surgery Centers 
(AAASC) and FASA, physician specialty societies, and nine ASCs. 

Analysis of Additional Services: 

To compare the delivery of additional services provided with procedures 
performed in ASCs and hospital outpatient departments, we identified 
all additional services frequently billed in each setting when one of 
the top 20 procedures with the highest Medicare ASC claims volume is 
performed. These procedures represented approximately 75 percent of all 
Medicare ASC claims in 2003. Using Medicare claims data for 2003, we 
identified beneficiaries receiving one of the top 20 procedures in 
either an ASC or hospital outpatient department, then identified any 
other claims for those beneficiaries from ASCs, hospital outpatient 
departments, durable medical equipment suppliers, and other Medicare 
part B providers. We identified claims for the beneficiaries on the day 
the procedure was performed and the day after.[Footnote 20] We created 
a list that included all additional services that were billed at least 
10 percent of the time with each of the top 20 procedures when they 
were performed in ASCs. We created a similar list of additional 
services for each of the top 20 procedures when they were performed in 
hospital outpatient departments. We then compared the lists for each of 
the top 20 procedures between the two settings to determine whether 
there were similarities in the additional services that were billed to 
Medicare. To compare the Medicare payments for procedures performed in 
ASCs and hospital outpatient departments, we identified whether any 
additional services included in our analysis resulted in an additional 
payment. 

We used Medicare claims data from the National Claims History (NCH) 
files. These data, which are used by the Medicare program to make 
payments to health care providers, are closely monitored by both CMS 
and the Medicare contractors that process, review, and pay claims for 
Medicare services. The data are subject to various internal controls, 
including checks and edits performed by the contractors before claims 
are submitted to CMS for payment approval. Although we did not review 
these internal controls, we did assess the reliability of the NCH data. 
First, we reviewed all existing information about the data, including 
the data dictionary and file layouts. We also interviewed experts at 
CMS who regularly use the data for evaluation and analysis. We found 
the data to be sufficiently reliable for the purposes of this report. 

Comparison of Per-Procedure Costs: 

To compare the relative costs of procedures performed in ASCs and 
hospital outpatient departments, we first compiled information on ASCs' 
costs and procedures performed. Because there were no recent existing 
data on ASC costs, we surveyed 600 ASCs, randomly selected from all 
ASCs, to obtain their 2004 cost and procedure data. We received 
response data from 397 ASC facilities. We assessed the reliability of 
these data through several means. We identified incomplete and 
inconsistent survey responses within individual surveys and placed 
follow-up calls to respondents to complete or verify their responses. 
To ensure that survey response data were accurately transferred to 
electronic files for our analytic purposes, two analysts independently 
entered all survey responses. Any discrepancies between the two sets of 
entered responses were resolved. We performed electronic testing for 
errors in accuracy and completeness, including an analysis of costs per 
procedure. As a result of our data reliability testing, we determined 
that data from 290 responding facilities were sufficiently reliable for 
our purposes. Our nonresponse analysis showed that there was no 
geographic bias among the facilities responding to our survey. The 
responding facilities performed more Medicare services than the average 
for all ASCs in our sample. 

To allocate ASCs' total costs among the individual procedures they 
perform, we developed a method to allocate the portion of an ASC's 
costs accounted for by each procedure. We constructed a relative weight 
scale for Medicare ASC-approved procedures that captures the general 
variation in resources associated with performing different procedures. 
The resources we used were the clinical staff time, surgical supplies, 
and surgical equipment used during the procedures. We used cost and 
quantity data on these resources from information CMS had collected for 
the purpose of setting the practice expense component of physician 
payment rates. For procedures for which CMS had no data on the 
resources used, we used information we collected from medical specialty 
societies and physicians who work for CMS. We summed the costs of the 
resources for each procedure and created a relative weight scale by 
dividing the total cost of each procedure by the average cost across 
all of the procedures. We assessed the reliability of these data 
through several means. We compared electronic CMS data with the 
original document sources for a large sample of records, performed 
electronic testing for errors in accuracy and completeness, and 
reviewed data for reasonableness. Based on these efforts, we determined 
that data were sufficiently reliable for our purposes. 

To calculate per-procedure costs with the data from the surveyed ASC 
facilities, we first deducted costs that Medicare considers 
unallowable, such as advertising and entertainment costs. (See fig. 3 
for our per-procedure cost calculation methodology.) We also deducted 
costs for services that Medicare pays for separately, such as physician 
and nonphysician practitioner services. We then separated each 
facility's total costs into its direct and indirect costs. We defined 
direct costs as those associated with the clinical staff, equipment, 
and supplies used during the procedure. Indirect costs included all 
remaining costs, such as support and administrative staff, building 
expenses, and outside services purchased. To allocate each facility's 
direct costs across the procedures it performed, we applied our 
relative weight scale. We allocated indirect costs equally across all 
procedures performed by the facility. For each procedure performed by a 
responding ASC facility, we summed its allocated direct and indirect 
costs to determine a total cost for the procedure. To obtain a per- 
procedure cost across all ASCs, we arrayed the calculated costs for all 
ASCs performing that procedure and identified the median cost. 

Figure 3: ASC Per-Procedure Cost Calculations from ASC Survey: 

[See PDF for image] 

Source: GAO. 

[End of figure] 

To compare per-procedure costs for ASCs and hospital outpatient 
departments, we first obtained from CMS the list of ambulatory payment 
classification (APC) groups used for the outpatient prospective payment 
system (OPPS) and the procedures assigned to each APC group. We also 
obtained from CMS the OPPS median cost of each procedure and the median 
cost of each APC group. We then calculated a ratio between each 
procedure's ASC median cost, as determined by the survey, and the 
median cost of each procedure's corresponding APC group under the OPPS, 
referred to as the ASC-to-APC cost ratio. We also calculated a ratio 
between each ASC procedure's median cost under the OPPS and the median 
cost of the procedure's APC group, using the data obtained from CMS, 
referred to as the OPPS-to-APC cost ratio. To evaluate the difference 
in procedure costs between the two settings, we compared the ASC-to-APC 
and OPPS-to-APC cost ratios. To assess how well the relative costs of 
procedures in the OPPS, defined by their assignment to APC groups, 
reflect the relative costs of procedures in the ASC setting, we 
evaluated the distribution of the ASC-to-APC and OPPS-to-APC cost 
ratios. 

Analysis of Labor-Related Costs: 

To calculate the percentage of labor-related costs among our sample 
ASCs, for each ASC, we divided total labor costs by total costs, after 
deducting costs not covered by Medicare's facility payment. We then 
determined the range of the percentage of labor-related costs among all 
of our ASCs and between the 25th percentile and the 75th percentile, as 
well as the mean and median percentage of labor-related costs. 

We performed our work from April 2004 through October 2006 in 
accordance with generally accepted government auditing standards. 

[End of section] 

Appendix III:  Additional Procedures Billed with the Top 20 ASC 
Procedures, 2003:  

Medicare ASC procedure volume ranking: 1; 
Procedure: Cataract surgery with intraocular lens insertion, one stage; 
Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Medicare ASC procedure volume ranking: 2; 
Procedure: Colonoscopy, with diagnosis; 
Additional procedure: Upper gastrointestinal (GI) endoscopy, with 
biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 11; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 12. 

Medicare ASC procedure volume ranking: 3; 
Procedure: After cataract laser surgery; 
Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Medicare ASC procedure volume ranking: 4; 
Procedure: Upper GI endoscopy, with biopsy; 
Additional procedure: Colonoscopy, with diagnosis; 
Times additional procedure was performed with procedure (percentage): 
ASC: 12; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 14. 

Medicare ASC procedure volume ranking: 5; 
Procedure: Colonoscopy, with lesion removal, snare technique; 
Additional procedure: Upper GI endoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 10; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 10. 

Medicare ASC procedure volume ranking: 5; 
Procedure: Colonoscopy, with lesion removal, snare technique; 
Additional procedure: Colonoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 14; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 22. 

Medicare ASC procedure volume ranking: 5; 
Procedure: Colonoscopy, with lesion removal, snare technique; 
Additional procedure: Colonoscopy, with lesion removal; 
Times additional procedure was performed with procedure (percentage): 
ASC: 10; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 14. 

Medicare ASC procedure volume ranking: 6; 
Procedure: Spine injection, lumbar, sacral; 
Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Medicare ASC procedure volume ranking: 7; 
Procedure: Colonoscopy, with biopsy; 
Additional procedure: Upper GI endoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 12; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 14. 

Medicare ASC procedure volume ranking: 7; 
Procedure: Colonoscopy, with biopsy; 
Additional procedure: Colonoscopy, with lesion removal; 
Times additional procedure was performed with procedure (percentage): 
ASC: 18; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 21. 

Medicare ASC procedure volume ranking: 8; 
Procedure: Colonoscopy, with lesion removal; 
Additional procedure: Upper GI endoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 10; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 10. 

Medicare ASC procedure volume ranking: 8; 
Procedure: Colonoscopy, with lesion removal; 
Additional procedure: Colonoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 11; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 15. 

Medicare ASC procedure volume ranking: 8; 
Procedure: Colonoscopy, with lesion removal; 
Additional procedure: Colonoscopy, with lesion removal, snare 
technique; 
Times additional procedure was performed with procedure (percentage): 
ASC: 23; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 32. 

Medicare ASC procedure volume ranking: 9; 
Procedure: Paravertebral injection, lumbar, sacral, add-on; 
Additional procedure: Spine injection, lumbar, sacral; 
Times additional procedure was performed with procedure (percentage): 
ASC: 13; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 12. 

Medicare ASC procedure volume ranking: 9; 
Procedure: Paravertebral injection, lumbar, sacral, add-on; 
Additional procedure: Paravertebral injection, lumbar, sacral, single 
level; 
Times additional procedure was performed with procedure (percentage): 
ASC:99; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 99. 

Medicare ASC procedure volume ranking: 10; 
Procedure: Injection foramen epidural, lumbar, sacral, single level; 
Additional procedure: Injection foramen epidural, lumbar, sacral, add-
on; 
Times additional procedure was performed with procedure (percentage): 
ASC: 39; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 36. 

Medicare ASC procedure volume ranking: 11; 
Procedure: Upper GI endoscopy, with diagnosis; 
Additional procedure: Dilate esophagus; 
Times additional procedure was performed with procedure (percentage): 
ASC: 12; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 9. 

Medicare ASC procedure volume ranking: 11; 
Procedure: Upper GI endoscopy, with diagnosis; 
Additional procedure: Colonoscopy, with diagnosis; 
Times additional procedure was performed with procedure (percentage): 
ASC: 17; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 19. 

Medicare ASC procedure volume ranking: 12; 
Procedure: Cystoscopy; 
Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Medicare ASC procedure volume ranking: 13; 
Procedure: Colon cancer screening, not high-risk individual; 
Additional procedure: Colonoscopy, with diagnosis; 
Times additional procedure was performed with procedure (percentage): 
ASC: 21; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 38. 

Medicare ASC procedure volume ranking: 14; 
Procedure: Paravertebral injection, lumbar, sacral, single level; 
Additional procedure: Spine injection, lumbar, sacral; 
Times additional procedure was performed with procedure (percentage): 
ASC: 14; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 13. 

Medicare ASC procedure volume ranking: 14; 
Procedure: Paravertebral injection, lumbar, sacral, single level; 
Additional procedure: Paravertebral injection, lumbar, sacral, add-on; 
Times additional procedure was performed with procedure (percentage): 
ASC: 86; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 79. 

Medicare ASC procedure volume ranking: 15; 
Procedure: Colorectal screening for high-risk individual; 
Additional procedure: Colonoscopy, with diagnosis; 
Times additional procedure was performed with procedure (percentage): 
ASC: 24; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 49. 

Medicare ASC procedure volume ranking: 16; 
Procedure: Carpal tunnel surgery; Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Medicare ASC procedure volume ranking: 17; 
Procedure: Repair of hammertoe; 
Additional procedure: Release of foot contracture; 
Times additional procedure was performed with procedure (percentage): 
ASC: 16; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 15. 

Medicare ASC procedure volume ranking: 17; 
Procedure: Repair of hammertoe; 
Additional procedure: Correction of bunion; 
Times additional procedure was performed with procedure (percentage): 
ASC: 11; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 13. 

Medicare ASC procedure volume ranking: 17; 
Procedure: Repair of hammertoe; 
Additional procedure: Correction of bunion with metatarsal osteotomy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 18; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 20. 

Medicare ASC procedure volume ranking: 18; 
Procedure: Injection foramen epidural, lumbar, sacral, add-on; 
Additional procedure: Injection foramen epidural, lumbar, sacral, 
single level; 
Times additional procedure was performed with procedure (percentage): 
ASC: 99; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 99. 

Medicare ASC procedure volume ranking: 19; 
Procedure: Upper GI endoscopy, with insertion of guide wire; 
Additional procedure: Upper GI endoscopy, with biopsy; 
Times additional procedure was performed with procedure (percentage): 
ASC: 50; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: 39. 

Medicare ASC procedure volume ranking: 20; 
Procedure: Spinal injection, cervical or thoracic; 
Additional procedure: None; 
Times additional procedure was performed with procedure (percentage): 
ASC: N/A; 
Times additional procedure was performed with procedure (percentage): 
Hospital outpatient department: N/A. 

Source: GAO analysis of CMS data. 

Note: N/A = not applicable. 

[End of table] 

[End of section] 

Appendix IV: Comments from the Centers for Medicare & Medicaid 
Services: 

Department Of Health & Human Services: 
Centers for Medicare & Medicaid services: 
Administrator: 
Washington, DC 20201: 

Date: Oct 24 2006: 

To: Kathleen M. King: 
Director, Health Care Government Accountability Office: 

From: Leslie V. Norwalk, Acting Administrator: 

Subject: Government Accountability Office's Draft Report: "Medicare: 
Payment for Ambulatory Surgical Centers Should Be Based on the Hospital 
Outpatient Payment System" (GAO-07-86): 

Thank you for the opportunity to review and comment on the Government 
Accountability Office's (GAO) draft report entitled, "MEDICARE: Payment 
for Ambulatory S surgical Centers Should Be Based on the Hospital 
Outpatient Payment System." 

Our goal in reforming the ambulatory surgical center (ASC) payment 
system is :o help Medicare beneficiaries receive the outpatient care 
they need in the most appropriate setting by eliminating payment 
differences that inappropriately favor one outpatient setting over 
another°r and that may add to Medicare costs. The Medicare Prescription 
Drug, Improvement, and Modernization Act of 2003 (MMA) requires the 
Secretary to implement a revised payment system I or surgical services 
furnished in ASCs no later than January 1, 2008, taking into account 
the recommendation of this GAO report, The MMA also requires that the 
revised payment system in its first year of implementation result in 
the same aggregate amount of expenditures as the current system. 

GAO Recommendation: 

The Administrator of the Centers for Medicare & Medicaid Services (CMS) 
implement a payment system for procedures performed in ASCs based on 
the outpatient prospective payment system (OPPS). The Administrator 
should take into account the lower relative c cost of procedures 
performed in ASCs compared to hospital outpatient departments in 
determining ASC payment rates. 

CMS Response: 

Consistent with the recommendation and the MMA requirements, on August 
8, CMS proposed a revised ASC payment system based on the OPPS that 
would provide for more appropriate payment for the broad range of 
services that ASCs can provide. The proposed revisions more closely 
align payments in the ASC and OPPS payment systems, to encourage the  
most efficient and appropriate choices of outpatient settings for 
ambulatory surgical procedures. 

We thank GAO for their analysis and are pleased that the recommendation 
is consistent with our proposed revisions to the ASC payment system for 
calendar year 2008. 

[End of section] 

Appendix V: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

Kathleen King, (202) 512-7119 or kingk@gao.gov: 

Acknowledgments: 

In addition to the contact named above, key contributors to this report 
were Nancy A. Edwards, Assistant Director; Kevin Dietz; Beth Cameron 
Feldpush; Marc Feuerberg; and Nora Hoban. 

FOOTNOTES 

[1] Omnibus Reconciliation Act of 1980 (ORA), Pub. L. No. 96-499, § 
934(b), 94 Stat. 2599, 2637 (codified, as amended, at 42 U.S.C. § 
1395l(i)). 

[2] ASC payment rates have been periodically updated for inflation. 

[3] MMA, Pub. L. No. 108-173, § 626(d), 117 Stat. 2066, 2319-2320 
(codified at 42 U.S.C. § 1395l note). 

[4] For the remainder of the report, we refer to these as the top 20 
procedures. 

[5] For Medicare payment purposes, the bills that providers submit for 
payment are referred to as claims. 

[6] We included services delivered the day after a procedure to allow 
for the inclusion of services, such as laboratory services, that may 
not be provided immediately following the procedure. 

[7] ORA, Pub. L. No. 96-499, § 934, 94 Stat. 2599, 2637-2639 (codified, 
as amended, at 42 U.S.C. § 1395l(i)). 

[8] Balanced Budget Act of 1997, Pub. L. No. 105-33, § 4523, 111 Stat. 
251, 445-450 (codified, as amended, at 42 U.S.C. § 1395l(t)). 

[9] There are a limited number of implantable devices that are 
considered new technology devices for which the hospital outpatient 
department may bill and receive separate payment. 

[10] ORA, Pub. L. No. 96-499, § 934(b), 94 Stat. 2599, 2637 (codified, 
as amended, at 42 U.S.C. § 1395l(i)). Congress later changed this 
requirement to an annual review and update of ASC payment rates. 
Omnibus Budget Reconciliation Act of 1986, Pub. L. No. 99-509, § 
9343(b), 100 Stat. 1874, 2040 (codified, as amended, at 42 U.S.C. § 
1395l(i)). 

[11] Social Security Act Amendments of 1994, Pub. L. No. 103-432, § 
141, 108 Stat. 4398, 4424-4426 (codified, as amended, at 42 U.S.C. § 
1395l(i)). 

[12] 63 Fed. Reg. 32,290, 32,307-308 (June 12, 1998). 

[13] MMA, Pub. L. No. 108-173, § 626(b), 117 Stat. 2066, 2319 
(codified, as amended, at 42 U.S.C. § 1395l(i)). 

[14] 71 Fed. Reg. 49,505 (Aug. 23, 2006). 

[15] Hospitals set charges for their services that are generally above 
the costs of the services. A cost-to-charge ratio is a calculation that 
describes the cost and charge relationship for services provided in a 
specific hospital. 

[16] The Medicare, Medicaid, and SCHIP Balanced Budget Refinement Act 
of 1999, Pub. L. No. 106-113, App. F, § 201(h), 113 Stat. 1501A-321, 
1501A-340 (codified, as amended, at 42 U.S.C. § 1395l(t)). 

[17] In our analysis, we included only those services billed with a 
procedure at least 10 percent of the time in either the ASC or hospital 
outpatient department setting. 

[18] APCs' median costs are determined from the costs of all of the 
services included within the APC. 

[19] If the median cost of an ASC procedure and the median cost of its 
respective APC group were equal, the cost ratio would be 1.00. 

[20] We included services delivered the day after a procedure to allow 
for the inclusion of services, such as laboratory services, that may 
not be provided immediately following the procedure. 

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