The Bond Improvement and Reclamation Assurance Act amends federal coal mining regulations to strengthen financial protections for reclamation of mined land. The bill requires mining companies to post performance bonds that are sufficient to cover the full cost of reclamation if the government has to complete the work after a mine closes, with a minimum bond amount of $52,593 annually adjusted for inflation. Mining companies and their major investors must remain liable for all reclamation costs even if a mine is sold to a new operator, and bond amounts must be recalculated whenever a permit is transferred, renewed, or significantly revised. The bill also requires federal inspectors to alert regulators when site conditions change in ways that might increase reclamation costs, so bond amounts can be adjusted accordingly. The Department of Interior must issue implementing regulations within 90 days of the bill's enactment that establish minimum bond guidelines based on actual costs from previous reclamation projects completed after bond forfeitures.