States trying to require drug testing for welfare recipients are facing obstacles, including legal challenges and high costs, The New York Times reports.

So far, the impact of the laws has been limited, the newspaper notes. Drug-testing measures generally have not found many drug users.

In 2011, a federal judge halted a Florida law that required welfare applicants to pass a drug test before they could receive benefits. The ruling was in response to a lawsuit filed by the American Civil Liberties Union of Florida. A similar law passed in Georgia was suspended as a result of the ruling. Other state laws have been moderated in an effort to lower costs and avoid legal fights.

Michigan lawmakers last week approved a bill that would withhold unemployment compensation from people who fail drug tests administered as part of a job interview. Prospective employers would screen applicants. They would not be forced to conduct the drug screening, and would not have to report the results.

Texas, Kansas and North Carolina have also passed drug-testing laws this year. In addition, 10 states considered testing laws for unemployment benefits, and two passed. The North Carolina measure only applies to welfare applicants who show “reasonable suspicion” of substance abuse, determined through questionnaires and background checks. Governor Pat McCrory vetoed the bill, saying similar laws in other states have been costly and ineffective. The legislature overrode his veto in September. The governor said his administration will stall implementation of the measure until enough funding for the program is provided.

At least 29 states this year considered drug-testing measures for people receiving welfare, but only two measures passed. Since 2011, only nine states have passed drug-testing bills related to welfare, and at least six have passed bills related to unemployment benefits. Last year, Wisconsin repealed a law requiring employers to report failed tests.