415 U.S. 199 (1974) Cited 909 times 1 Legal Analyses
Holding that “[t]he power of an administrative agency to administer a congressionally created and funded program necessarily requires the formulation of policy and the making of rules to fill any gap left, implicitly or explicitly, by Congress” but noting that “[n]o matter how rational or consistent with congressional intent a particular decision might be, [such decision] cannot be made on an ad hoc basis ...”