Given the unique eligibility criteria for the Category 1, 2, or 3 grants, FTA will only permit budget revisions that meet the below criteria with prior FTA approval. Budget revisions will only be permitted to shift funds from an existing Category 2 Activity Line Item (ALI) when a cost-savings is realized to another existing Category 2 ALI, should there be a cost-overrun or need for additional funds. Grantees will be required to submit documentation demonstrating the cost savings and cost over-run involved in the budget revision. If the grantee experiences a cost-savings or determines it no longer needs the funds obligated in other ALIs in its Category 1, 2, and 3 grant, then the excess funds will be deobligated. Funds that are deobligated from the grant may be available for future obligation by the grantee, should the grantee have additional eligible recovery costs that cannot be funded by its pro-rated allocation or its insurance proceeds.