49 U.S. Code § 14503. Withholding State and local income tax by certain carriers
(a) Single State Tax Withholding.—
(1) In general.—
No part of the compensation paid by a motor carrier providing transportation subject to jurisdiction under subchapter I of chapter 135 or by a motor private carrier to an employee who performs regularly assigned duties in 2 or more States as such an employee with respect to a motor vehicle shall be subject to the income tax laws of any State or subdivision of that State, other than the State or subdivision thereof of the employee’s residence.
(2) Employee defined.—
In this subsection, the term “employee” has the meaning given such term in section 31132.
(b) Special Rules.—
(1) Calculation of earnings.—
(2) Water carriers.—A water carrier providing transportation subject to jurisdiction under subchapter II of chapter 135 shall file income tax information returns and other reports only with—
(c) Filing of Information.—