24 CFR § 5.628 - Total tenant payment.
(a) Determining total tenant payment (TTP). Total tenant payment is the highest of the following amounts, rounded to the nearest dollar:
(1) 30 percent of the family's monthly adjusted income;
(2) 10 percent of the family's monthly income;
(3) If the family is receiving payments for welfare assistance from a public agency and a part of those payments, adjusted in accordance with the family's actual housing costs, is specifically designated by such agency to meet the family's housing costs, the portion of those payments which is so designated;
(4) The minimum rent, as determined in accordance with § 5.630; or
(5) For public housing only, the alternative non-public housing rent, as determined in accordance with § 960.102 of this title.
(b) Determining TTP if family's welfare assistance is ratably reduced. If the family's welfare assistance is ratably reduced from the standard of need by applying a percentage, the amount calculated under paragraph (a)(3) of this section is the amount resulting from one application of the percentage.