As congressional Democrats ready plans to strengthen federal wage and hour law, several states already have implemented measures to ensure workers get paid for all of their work time. Colorado last month became the latest state to pass a law directly addressing wage “theft,” joining California, Illinois, New York, Oregon and Texas, as well as the District of Columbia.

Thirty Nine More: Another 39 states have laws with remedies and penalties for violations related to minimum wage, overtime, and wage-payment requirements, according to Bloomberg Law data.

Federal Bill Coming: Rep. Rosa DeLauro (D-Conn.) and Sen. Patty Murray (D-Wash.) plan to...