HUD has published the Housing Choice Voucher 2018 Administrative Fee Rates. Administrative fee revenue earned will be calculated using the same methodology as in previous years. The first 600 units leased each month will earn the A rate. All units leased over 600 (601+) will earn the B rate. The current proration rate is 77%. (source: BDO PHA Finance via Texas Housing Association)
Below are the explanation document and the rates for Texas PHAs.