(a) Time for filing. The State must file its request for review within 90 days after the date of the notice of assessment, allowance, or disallowance. Usually, the date of the request for review is considered the filing date. Where the 90-day period ends on a weekend, legal holiday or Federal nonworkday, a request filed on the next Federal workday is considered as timely filed.

(b) Extension of time. For good cause shown, and upon written application by a State filed prior to the expiration of the time for filing a request for review, additional time for filing the request may be allowed.