Some states and countries allow taxpayers to prepare and file tax returns on their Internet Web sites at no charge, an option not available to federal taxpayers. Such a service might mitigate the concerns taxpayers have about current electronic filing options, which require filing through a third party and may involve fees. Increased electronic filing would reduce IRS's paper processing costs, reduce transcription errors, and speed up refunds. However, the idea is controversial. IRS already has a Free File program which offers free return preparation and filing by private companies for some people via IRS's Web site. Some are opposed to IRS competing with tax preparation software companies. GAO was asked to (1) describe IRS's options for on-line preparation and filing (I-file) based on states' experiences; (2) determine the benefits and costs of I-file based on the experiences of the states; and (3) describe the potential for IRS to realize cost savings from I-file. GAO profiled 7 states and the District of Columbia, 2 foreign countries and 3 federal agencies to describe I-file options and determine their benefits and costs.