(a) An agency with at least 1,000 employees in the general category of employees or 500 employees in any of the special categories may appeal to the Board the normal cost percentage for that category as applied to that agency.

(b) No appeal will be considered by the Board unless the agency files, no later than 6 months after the date of publication of the notice of normal cost percentages under § 841.407, a petition for appeal that meets all the requirements of § 841.410.