1. Short title This Act may be cited as the Public Housing for the 21st Century Act of 2023 . 2. Congressional findings The Congress finds that— (1) roughly half of renter households in the United States—more than 21 million—are cost-burdened, meaning they spend more than 30 percent of their income on rent; (2) the greatest need for affordable housing is among people with extremely low incomes, 73 percent of whom pay more than half of their income on rent; (3) however, the production of new affordable rental dwelling units is often constrained by the availability of Federal subsidies and too often existing Federal subsidies are not deeply targeted enough to serve households with the greatest needs; (4) faced with such constraints, State and local public developers are building dwelling units affordable to extremely low-, very low-, low-, and moderate-income households by leveraging local policy tools, reforming zoning and land use restrictions, adopting innovative financing mechanisms, and utilizing market rate units to cross-subsidize below-market, affordable units; and (5) such mixed-income public housing promotes the financial stability and proper maintenance of housing developments, fosters community diversity and integration, and allows scarce Federal subsidies to be targeted to the most vulnerable households. 3. Training and technical assistance regarding mixed-income public housing best practices (a) In general Not later than the expiration of the 12-month period beginning on the date of the enactment of this Act, the Secretary of Housing and Urban Development shall— (1) identify best practices and models relevant to developing mixed-income, publicly owned housing to increase the supply of housing dwelling units that are affordable to extremely low-, very low-, low-, and moderate-income households, that provide permanent affordability and that limit Federal subsidies to costs associated with building or preserving units affordable to extremely low-income households