42 C.F.R. § 423.2114
The Council dismisses a request for review if the enrollee requesting review did not file the request within the stated period of time and the time for filing has not been extended. The Council also dismisses the request for review if—
[74 FR 65363, Dec. 9, 2009, as amended at 82 FR 5138, Jan. 17, 2017]