Section 1818A, established by Section 6012 of P.L 101-239, provides that disabled
            individuals who lose or have lost Medicare coverage solely due to their earnings from
            substantial gainful activity (SGA) may enroll in Medicare Part A Premium-Hospital
            Insurance (HI) when their premium-free HI ends. To be eligible for Premium-HI under
            this section, the individual must continue to have a disabling impairment. They must
            also apply for coverage during a proper enrollment period. These individuals may enroll
            in Medicare Part B Supplementary Medical Insurance because they are entitled to Part
            A. The first possible month of entitlement to Premium-HI for the Working Disabled
            is July 1990.
         
         The Office of Disability and International Operations (ODIO) and the Program Service
            Centers (PSCs) review the claims folders of individuals who apply for coverage to
            verify that they meet the requirements for entitlement to Premium-HI (i.e., SGA cessation,
            timely enrollment, current disability). ODIO and the PSC prepare determinations on
            an SSA-831-U3.
         
         Any case in which ODIO or the PSC cannot determine whether the individual continues
            to have a disabling impairment is sent to the DDS for a continuing disability review
            (CDR). The DDS prepares determinations on an SSA-833-U3.