Comparison definition. 'Both are essentially doctrines of comity between courts and agencies. They are two sides of the timing coin: Each determines whether an action may be brought in a court or whether an agency proceeding, or further agency proceeding, is necessary.' (Schwartz, Administrative Law (1984) § 8.23, p. 485.)
In Western Pacific, supra, 352 U.S. 59, the high court explained: ' 'Exhaustion' applies where a claim is cognizable in the first instance by an administrative agency alone; judicial interference is withheld until the administrative process has run its course. 'Primary jurisdiction,' on the other hand, applies where a claim is originally cognizable in the courts, and comes into play whenever enforcement of the claim requires the resolution of issues which, under a regulatory scheme, have been placed within the special competence of an administrative body; in such a case the judicial process is suspended pending referral of such issues to the administrative body for its views.' (Id., at pp. 63-64 [1 L.Ed.2d at p. 132], italics added; see also Schwartz, supra, § 8.23 at p. 486 ['Exhaustion applies where an agency alone has exclusive jurisdiction over a case; primary jurisdiction where both a court ...