Rehabilitation for Multiemployer Pensions Act This bill establishes the Pension Rehabilitation Administration within the Department of the Treasury and a related trust fund to make loans to certain multiemployer defined benefit pension plans. To receive a loan, a plan must be either in critical and declining status (including any plan with respect to which a suspension of benefits has been approved) or insolvent, if the plan became insolvent after December 16, 2014, and has not been terminated. Treasury must issue bonds to fund the loan program and transfer amounts equal to the proceeds to the trust fund established by this bill. The Pension Rehabilitation Administration may use the funds, without a further appropriation, to make loans, pay principal and interest on the bonds, or for administrative and operating expenses. The bill amends the Employee Retirement Income Security Act of 1974 (ERISA) to allow the sponsor of a multiemployer pension plan that is applying for a loan under this bill to also apply to the Pension Benefit Guaranty Corporation (PBGC) for financial assistance if, after receiving the loan, the plan will still become (or remain) insolvent within the 30-year period beginning on the date of the loan. The bill also appropriates to the PBGC the funds that are necessary to provide the financial assistance required by this bill.