Section 990.110 - Operating fund formula(a)General formula.(1) The amount of annual contributions (operating subsidy) each PHA is eligible to receive under this part shall be determined by a formula.(2) In general, operating subsidy shall be the difference between formula expense and formula income. If a PHA's formula expense is greater than its formula income, then the PHA is eligible for an operating subsidy.(3) Formula expense is an estimate of a PHA's operating expense and is determined by the following three components: Project Expense Level (PEL), Utility Expense Level (UEL), and other formula expenses (add-ons). Formula expense and its three components are further described in subpart C of this part. Formula income is an estimate for a PHA's non-operating subsidy revenue and is further described in subpart D of this part.(4) Certain portions of the operating fund formula (e.g., PEL) are calculated in terms of per unit per month (PUM) amounts and are converted into whole dollars by multiplying the PUM amount by the number of eligible unit months (EUMs). EUMs are further described in subpart B of this part.(b)Specific formula.(1) A PHA's formula amount shall be the sum of the three formula expense components calculated as follows: {[(PEL multiplied by EUM) plus (UEL multiplied by EUM) plus add-ons] minus (formula income multiplied by EUM)}.(2) A PHA whose formula amount is equal to or less than zero is still eligible to receive operating subsidy equal to its most recent actual audit cost for its Operating Fund Program.(3) Operating subsidy payments will be limited to the availability of funds as described in § 990.210(c) .(c)Non-codified formula elements. This part defines the major components of the Operating Fund Formula and describes the relationships of these various components. However, this part does not codify certain secondary elements that will be used in the revised Operating Fund Formula. HUD will more appropriately provide this information in non-codified guidance, such as a Handbook, FEDERAL REGISTER notice, or other non-regulatory means that HUD determines appropriate.