The MBTA Communities Law (Massachusetts General Laws Chapter 40A, Section 3A) requires municipalities served by the Massachusetts Bay Transportation Authority (MBTA) to create zoning districts that allow multi-family housing by-right. These districts must meet specific criteria, such as minimum density requirements, and be located near public transit stations. Enacted in 2021, the law aims to address the state’s housing crisis by encouraging affordable, diverse, and transit-oriented development. Compliance is mandatory for access to certain state funding programs. Municipalities are tasked with ensuring zoning aligns with the law’s goals of increasing housing supply while promoting sustainable and equitable growth.