43 CFR § 2805.17 - When do I pay monitoring fees?
(c) Monitoring Category 6. BLM may periodically estimate the costs of monitoring your use of the grant. BLM will include this fee in the costs associated with processing fees described at § 2804.14 of this part. If BLM has underestimated the monitoring costs, we will notify you of the shortfall. If your payments exceed the reasonable costs that Federal employees incurred for monitoring, BLM will either reimburse you the difference, or adjust the next billing to reflect the overpayment. Unless BLM gives you written authorization, you may not offset or deduct the overpayment from your payments.