5 U.S.C. § 5517: Withholding State income taxes

provides for the collection of a tax either by imposing on employers generally the duty of withholding sums from the pay of employees and making returns of the sums to the State, or by granting to employers generally the authority to withhold sums from the pay of employees if any employee voluntarily elects to have such sums withheld; and imposes the duty or grants the authority to withhold generally with respect to the pay of employees who are residents of the State; This section does not give the consent of the United States to the application of a statute which imposes more burdensome requirements on the United States than on other employers, or which subjects the United States or its employees to a penalty or liability because of this section. An agency of the United States may not accept pay from a State for services performed in withholding State income taxes from the pay of the employees of the agency. For the purpose of this section, “State” means a State, territory, possession, or commonwealth of the United States. participation in exercises or the performance of duty under section 502 of title 32 , United States Code, by a member of the National Guard; and participation in scheduled drills or training periods, or service on active duty for training, under section 10147 of title 10 , United States Code, by a member of the Ready Reserve.