24 CFR §232.11

1. (a)To be eligible for insurance under this part, and except with respect to Supplemental Loans to Finance Purchase and Installation of Fire Safety Equipment (subpart C of this part), if HUD determines the mortgage presents an atypical long-term risk, HUD may require that the borrower establish, at final closing and maintain throughout the term of the mortgage, a long-term debt service reserve account.
2. (b)The long-term debt service reserve account, if required, may be financed as part of the initial mortgage amount, provided that the maximum mortgage amount as otherwise calculated is not thereby exceeded.
3. (c)The amount required to be initially placed in the long-term debt service reserve account and the minimum long-term balance to be maintained in that account will be determined during underwriting and separately identified in the firm commitment. Although HUD may, when appropriate to avert a mortgage insurance claim, permit the balance to fall below the required minimum long-term balance, the borrower may not take any distribution of mortgaged property except when both the long-term debt service reserve account is funded at the minimal long-term level and such distribution is otherwise permissible.