This document provides information about Chapter 40R, a Massachusetts law that provides incentives for municipalities to create dense, mixed-use zoning districts. It outlines the basic requirements for 40R districts, including minimum allowable densities between 8-20 units per acre depending on building type. Districts must have a 20% affordability requirement for projects with 13 or more units. Municipalities can receive payments for adopting 40R districts ranging from $10,000 to $600,000 based on number of zoned units, as well as $3,000 per unit in density bonus payments.