24 CFR §203.33

1. (a)Adequacy of mortgagor's gross income. A mortgagor must establish, to the satisfaction of the Secretary, that his or her gross income is and will be adequate to meet (1) the periodic payments required by the mortgage submitted for insurance and (2) other long-term obligations.
2. (b)Determinations of adequacy of mortgagor income under this section shall be made in a uniform manner without regard to race, color, religion, sex, national origin, familial status, handicap, marital status, actual or perceived sexual orientation, gender identity, source of income of the mortgagor, or location of the property.