Yes. Treasury Regulation 1.48-12(d)(7)(ii) states that if the final certification of completed work has not been issued by the Secretary of Interior at the time the tax return is filed for a year in which the credit is claimed, a copy of the first page of Part 2 of the Historic Preservation Certification Application must be attached to Form 3468 filed with the tax return. The taxpayer must reasonably expect that they will receive final approval and that their project will be certified by the National Park Service.

Final certification by the Department of Interior is required. If the taxpayer fails to receive final certification within 30 months after the date the taxpayer filed a tax return on which the credit was claimed, the taxpayer must agree to extend the period of assessment for any tax relating to the time for which the credit was claimed. If the final certification is denied by the Department of Interior, the credit will be disallowed for any taxable year in which it was claimed.