If you review applicant or employee credit reports, you're undoubtedly already familiar with the Fair Credit Reporting Act (FCRA). Among other things, this federal law requires employers to get the consent of the employee or applicant before pulling credit and other consumer reports, to give notice if the information in the report might lead you to take adverse action (such as denying the applicant a job or denying the employee a promotion), and to give notice -- again -- if you do ultimately take the adverse action.
As long as you follow the rules above, the FCRA allows you to use credit reports for employment purposes, including to decide whether to hire, promote, or even fire. That's the federal law, however; some states see things differently. The economic downturn of the last few years -- and the resulting damage to credit reports and scores -- have led many politicians to reconsider whether it's really appropriate for employers to use credit reports in making job decisions. At least three states (Hawaii, Oregon, and Washington) have passed laws prohibiting employers from considering credit reports in most circumstances. According to the National Conference of State Legislatures, about 20 states are currently considering similar legislation. (See their detailed chart here.)