Prioritize Housing for Homeless Veterans Act of 201 7 This bill requires the Department of Housing and Urban Development, in making certain Veterans Affairs-Supported Housing program funds available among public-housing agencies (PHAs) for rental voucher assistance for homeless veterans who have chronic mental illnesses or chronic substance-use disorders, to: (1) consider, together with current factors, the extent of availability in the areas served by PHAs of housing that is affordable to low-income families; and (2) give priority to metropolitan areas having an efficiency fair-market rent that has increased by more than 10% over the most recent five-year period for which such information is available.