"Substantial evidence" is the standard of review by the District Court; issues of credibility and drawing of permissable inferences are for the Secretary.

State, not federal law of divorce governs validity of claim. Even in the presence of substantial evidence, the Court may review conclusions of law.

A dismissal of a hearing request on res judicata grounds, where the current claim has the same factual basis as the earlier decision, is not reviewable. A purely discretionary hearing held for purposes of receiving allegedly new and material evidence is not a hearing within the meaning of 42 U.S.C.S. § 405(g). Claimant had the burden to show that his disability existed prior to his date last insured. Court reviews grant of summary judgment de novo. In social security disability cases, summary judgment procedure is not an invitation to the claimant to contradict the contents of that record or to introduce new or additional evidence. Reopenings are permitted for "good cause," if new and material evidence is presented. Absent a colorable constitutional claim, a district court does not have jurisdiction to review SSA's discretionary decision not to reopen an earlier adjudication.