A number of advocacy groups, such as the Medicare Rights Center, have begun to lobby Congress to revise a law that requires a two-year waiting period to become eligible for Medicare after they begin to receive Social Security disability benefits, USA Today reports. An estimated 400,000 uninsured U.S. residents with disabilities are waiting to become eligible for Medicare, according to a report released on Wednesday. The report, prepared by the center and funded by the Commonwealth Fund, profiles 21 individuals with disabilities who are waiting to become eligible for Medicare. Medicare implemented the waiting period in 1972, when the program expanded to cover individuals with disabilities, to limit the cost and ensure only those with severe and long-term disabilities would qualify for the program. However, advocacy groups hope that Congress will revise the law to eliminate or reduce the waiting period, and Rep. Gene Green (D-Texas) has introduced such legislation. However, past efforts to revise the law have failed, with the exception of a reduction in the waiting period for individuals with end-stage kidney disease or amyotrophic lateral sclerosis. In addition, Democratic lawmakers have "pledged to keep federal spending in check -- and to offset new spending with cuts elsewhere," and proposals to "help different groups of uninsured, particularly children, are also competing for attention and dollars," USA Today reports. Elimination of the waiting period could cost between $5 billion and more than $8 billion annually, although savings in Medicaid could offset some of the cost (Appleby, USA Today, 4/11).