Mortgage Bankers Association v. Seth Harris

Opinion for the Court by Circuit Judge BROWN.

BROWN, Circuit Judge:

The tandem of Paralyzed, Veterans of America v. D.C. Arena L.P., 117 F.3d 579 (D.C.Cir.1997) and Alaska Professional Hunters Ass’n v. FAA, 177 F.3d 1030 (D.C.Cir.1999) (‘Alaska Hunters ”) announced an ostensibly straightforward rule: “When an agency has given its regulation a definitive interpretation, and later significantly revises that interpretation, the agency has in effect amended its rule, something it may not accomplish [under the APA] without notice and comment.” Alaska Hunters, 177 F.3d at 1034. The only question…