This bill modifies certain requirements to assist Puerto Rico and the U.S. Virgin Islands in recovering from specified incidents relating to Hurricanes Irma and Maria. Specifically, the bill directs the Federal Emergency Management Agency (FEMA), in providing assistance for critical services for the duration of the recovery for such incidents, to revise specified guidance definitions to provide explicitly that multicomponent systems or facilities be inspected, evaluated, and estimated as a single project rather than requiring every component of the system to be inspected, evaluated, and estimated; put into effect, at the request of a disaster assistance applicant, a procedure for evaluation and authorization of projects through professionally licensed engineers; and extend the deadline to October 31, 2021, for the presentation of cost estimates and project worksheets. The bill requires (currently, authorizes) FEMA to provide specified assistance for critical services for the duration of the recovery. Public assistance program alternative procedures adopted by FEMA must ensure that work performed by providers, suppliers, and contractors to the federal, state, local, or tribal governments or nonprofit facilities is paid for and reimbursed in a timely manner. A local government or nongovernmental organization, in meeting any federal cost-sharing requirement, may use funds from any disaster recovery program or source to meet federal cost-sharing requirements with respect to such incidents.