"During 2010 and the first half of 2011, legislators in 31 states have proposed 82 bills that would require drug tests of TANF applicants and/or recipients.31 There was also one proposal each in the U.S. House of Representatives and Senate."
"The legislative proposals identified differ in the populations that would be subject to drug testing. Of the bills, 50 State bills plus the two congressional bills would require that applicants be tested, 35 State bills would require suspicionless testing of current recipients, and an additional 26 would test current recipients for cause. In addition, while nearly all bills focus on testing adult applicants or recipients, a small minority of State bills would require youth aged 13 or older be tested and proposed legislation in one State would require that all benefit recipients, including children under 12, be tested."
Note: The source for this fact also contains a list of 2010 and 2011 federal and state legislative proposals concerning TANF drug testing and legislative cost estimates from 12 states.
"Drug Testing Welfare Recipients: Recent Proposals and Continuing Controversies," Office of the Assistant Secretary for Planning and Evaluation (Washington, DC: October 2011), p. 5.