43 CFR § 3835.16
If I am a qualified small miner, and I obtained a waiver in one assessment year, what must I do if I want to pay the maintenance fee for the following assessment year?
June 11, 2020
(a) You must perform the required assessment work in the assessment year for which you obtained a waiver from payment of the annual maintenance fee, and file the annual FLPMA document required by the December 30th immediately following the payment of the maintenance fee; and
(b) You must pay the maintenance fee by the proper deadline for the following assessment year.