MD SB12

Landlords of apartment buildings with 4 or more units must provide air-conditioning capable of maintaining temperatures at or below 80°F at 3 feet above floor level in habitable spaces

Requirements apply from June 1 to September 30 each year, with landlords responsible for maintaining landlord-controlled systems or ensuring tenant-controlled systems are in good working order

Newly constructed rental units must comply beginning June 1, 2026; renovated units with electrical or heating system upgrades must comply beginning October 1, 2026

Exemptions include properties on the National Register of Historic Places, Housing Authority of Baltimore City developments built 1940-1950, and rowhouse public housing units acquired by Baltimore City Housing Authority between 1960-1997

The law applies only prospectively and does not affect buildings with permits issued before the June 1, 2026 effective date