Cert. denied, 107 S.Ct. 903 (1987). Claimant is not entitled to disability benefits unless he can demonstrate that his disability existed prior to the expiration of his insured status. Denial on severity grounds upheld. Epilepsy began after date last insured.

Neither absence of treatment records from relevant time period and retrospective nature of treating doctor's opinion justify ALJ's finding that treating source's report was too speculative a basis for establishing a severe impairment. (remanding for ALJ to obtain retrospective opinions regarding claimant's mental condition in relevant period). Because of plaintiff's readily apparent mental disorder and fact that the ALJ noticed the possibility that the disorder might be related to an event occurring prior to the date last insured., ALJ had duty to develop the record of the etiology of the illness, its course, and its severity. Fairness dictates that when a claimant obviously suffering from a severe mental disorder appears at a social security proceeding without counsel, the ALJ undertake to protect his interests at the hearing. ALJ's failure to develop evidence is good cause for remand. Claimant had burden of establishing by credible evidence that his mental impairment was of a disabling level of severity as of date last insured. It is not sufficient for him to establish that his mental impairment had its roots prior to that date.

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.