GAO discussed growth in the Supplemental Security Income (SSI) Program and changes in the characteristics of SSI recipients. GAO noted that: (1) since 1986, the number of disabled SSI recipients under age 65 has increased an average of over 8 percent annually, adding nearly 2 million younger recipients to the rolls, while the number of aged and blind recipients has remained constant; (2) the increase in younger beneficiaries, coupled with low exit rates, means that SSI costs will continue to increase in the near term; (3) if the growth in the number of younger recipients is not slowed, SSI will become even more costly in the long term; (4) since 1991, disabled children, legal immigrants, and adults with mental impairments have accounted for nearly 90 percent of the SSI caseload growth; (5) 5 percent of the 2 million mentally disabled adults are disabled principally by drug addiction or alcoholism; (6) financing substance abuse treatment programs for drug addicts and alcoholics may be more effective than providing cash payments to addicts; and (7) immigration policy regarding sponsorship requirements and changes in eligibility criteria should be reviewed to stem the influx of immigrants on SSI.