Thousands of public housing tenants are being forced to put their cigarettes out starting Monday.

NYCHA housing is becoming officially smoke-free based on a mandate from U.S. Housing and Urban Development, requiring all public housing to disallow smoking by July 30.

The goal is to create healthier homes for residents and employees.

The new policy prevents cigarettes, cigars, pipes and hookah pipes inside public housing units, administrative offices and in outdoor areas within 25 feet of NYCHA buildings.

Feds say smoking is the leading cause of preventable death in the United States, and secondhand smoke can trigger asthma and lead to strokes, heart attacks, cancer and respiratory illness.