MD HB1517

Creates protections for residential projects subject to "retaliatory downzoning," defined as when a local official publicly opposes a project, then enacts zoning changes reducing density on property zoned the same way for at least 25 consecutive years, and takes obstructive actions within 4 years contrary to planning department recommendations

Qualifying projects must include at least 15% affordable dwelling units deed-restricted for 40 years, or 20% in jurisdictions that already had equal or higher affordability requirements as of December 31, 2024

Local jurisdictions must allow qualified projects to exceed normal density limits: 60% above allowable density in multifamily zones or 50% of the previous zoning density (whichever is greater), and 60% more units in mixed-use zones

Permits middle housing units in single-family zones and mixed-use development in multifamily and nonresidential zones for qualified projects

Effective October 1, 2026