Saying Florida residents should not subsidize substance abusers, Gov. Rick Scott signed a bill that will require welfare recipients to submit to drug tests.

Applicants for the federal Temporary Assistance for Needy Families program who test positive for illegal substances will not be eligible for benefits for one year or until they complete a treatment program.

Liz Schott, a policy analyst at the Center on Budget and Policy Priorities in Washington, which focuses on public programs that affect low- and moderate-income families, said the measure signed into law by Mr. Scott, a Republican, was “about smearing people who are getting welfare.”