Employers in the United States are increasingly utilizing staffing firms, employee leasing firms, temporary employment agencies and other third parties to help manage contingent labor in their organizations. The use of such triangular relationships creates complexities in the rights and responsibilities of each party, partially due to the variation in how U.S. employment law defines employers and employees across statutes. We analyze the various definitions of employee and employer across key U.S. employment statutes (e.g., Civil Rights Act of 1964, ADA, FMLA, FLSA), tests used by the courts in their decision making, and IRS regulations and evaluate the impact of these definitions on the use of contingent employees in triangular relationships. We review existing case law relevant to discrimination and nondiscrimination statutes and identify key areas of risk and responsibility for both the individuals employed as contingent workers and firms that use contingent labor. Finally, we offer recommendations for strategically managing contingent labor in the current legal context.