As a condition of issuing a commitment, HUD shall require establishment of a Mortgage Reserve Fund (MRF). The mortgagor shall be required to make contributions to the MRF such that, with fund earnings, the MRF will build to one year of debt service at 5 years following commencement of amortization, increasing thereafter to 2 years of debt service on and after 10 years following commencement of amortization according to a schedule established by HUD, unless HUD determines that a different schedule of contributions is appropriate based on the mortgagor's risk profile, reimbursement structure, or other characteristics. In particular, hospitals that receive cost-based reimbursement may be required to have MRFs that build to more than 2 years of debt service. Expenditures from the fund are made at HUD's sole discretion or in accordance with the mortgagor's MRF Schedule. Upon termination of insurance, the balance of the MRF shall be returned to the mortgagor, provided that all obligations to HUD have been met.