issue final regulations to implement this subsection as amended by the Disaster Recovery Reform Act of 2018 . (iii) Waiver and expiration The authority under clause (i) and any pilot program implemented pursuant to such clause shall expire 2 years after the date of enactment of this paragraph or upon issuance of final regulations pursuant to clause (ii), whichever occurs sooner. . (b) Reimbursement The Federal Emergency Management Agency (FEMA) shall reimburse State and local units of government (for requests received within a period of 3 years after the declaration of a major disaster under section 401 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act ( 42 U.S.C. 5170 )) upon determination that a locally implemented housing solution, implemented by State or local units of government— (1) costs 50 percent of comparable FEMA solution or whatever the locally implemented solution costs, whichever is lower