18 CFR §1308.26

1. (a)An appeal to the Board from a Contracting Officer's decision under § 1308.12 shall be initiated within 90 days from the Contractor's receipt of the Contracting Officer's decision and in the manner set forth in the disputes clause.
2. (b)An appeal from the Contracting Officer's failure to render a timely decison shall be taken within the time period provided by § 1308.17. The notice of appeal shall be in the form and filed in the manner specified in the disputes clause, but shall state that it is an appeal under § 1308.17, and shall include a copy of the claim which was submitted for decision.