20 CFR §404.970, which lists four situations in which AC will review a case, is not an exhaustive list of all situations where Appeals Council may take review. Restrictive interpretation of AC's right to own motion review could interfere with administration of claims and monitoring of department. An ALJ's decision to give or deny credit to a particular witness's testimony should not be reversed absent an adequate explanation of the grounds for the reviewing body's source of disagreement with the ALJ. Court reverses where Appeals Council, on own motion review, finds no severe impairment but fails to state reasons for rejecting ALJ's credibility determination.

Own motion reopening by Appeals Council limited to 60 days; reopening after 60 days allowed only on the motion of claimants. Court gives considerable deference to an agency's interpretation of its own regulations,and construe the provisions of the relevant regulations and statutes to have cohesive meaning. Where only declaratory and injunctive relief sought, plaintiffs not required to identify class members once the existence of the class has been demonstrated. Courts have broad discretion to grant or deny class certification. Class certification issue remanded where plaintiff's lack of evidence supporting class certification was due to defendant's failure to respond to discovery requests.

Court affirms Appeals Council's finding that plaintiff's informal work relationship with his wife and mother-in-law did not constitute employment for purpose of old-age insurance coverage. In a case involving closely related and closely living individuals claiming an employer-employee relationship, the entire picture of the history and circumstances of the parties must be considered. Once Appeals Council takes jurisdiction of a case to review error of law, review can permissibly encompass the entire record.