20 C.F.R. § 418.3675
Our decision is binding unless you file an action in Federal district court seeking review of our final decision or we revise it as provided in § 418.3678 . You may file an action in Federal district court within 60 days after the date you receive notice of the decision. You may request that the time for filing an action in Federal district court be extended. The request must be in writing and it must give the reasons why the action was not filed within the stated time period. The request must be filed with the decision-maker who issued the final decision in your case. If you show that you had good cause for missing the deadline, we will extend the deadline. We will use the standards in § 418.3640 to decide if you had good cause to miss the deadline.
20 C.F.R. §418.3675