Agency's construction of statute was permissible, and made considerable sense in terms of the statute's basic objectives. In addition, the agency's regulations reflected the agency's own longstanding interpretation. An individual is not entitled to a trial work period if he or she performs work demonstrating the ability to engage in SGA within 12 months of the onset of the impairment(s) that prevented the performance of SGA and before the date of any notice of determination or decision finding that he or she is disabled. Duration requirement in the definition of disability means that both the medical impairment and the inability to engage in substantial gainful activity (SGA) must have lasted or be expected to last for a continuous period of not less than 12 months.

Although plaintiff has several impairments, court holds that there was considerable evidence in the record that he was able to work with these problems for many years. Further, plaintiff's mental impairment is found to be non-severe, although it moderately restricts five out of ten basic work-related functions. Claimant has the burden of proving that he is disabled at Step 4, meaning that he must prove that his disability is serious enough to prevent him from working at his former jobs. At Step 5, however, the Secretary must show that there are other jobs in the economy that claimant can nonetheless perform. Implying that claimant bears burden of proving three threshold steps. Meeting a listing automatically entitles claimant to benefits. Meeting a listing automatically entitles claimant to benefits.