26 USCS § 7421
26 USCS § 7421 withdraws jurisdiction from all courts, federal and state, over pre-enforcement challenges to the collection of taxes.
26 USCS § 7421(a). Prohibition of suits to restrain assessment or collection.
(a) Tax. Except as provided in sections 6015(e), 6212(a) and (c), 6213(a), 6225(b), 6246(b), 6330(e)(1), 6331(i), 6672(c), 6694(c), and 7426(a) and (b)(1), 7429(b), and 7436, no suit for the purpose of restraining the assessment or collection of any tax shall be maintained in any court by any person, whether or not such person is the person against whom such tax was assessed.
Its constitutionality was upheld against a challenge in Schildcrout v. McKeever, 580 F2d 994 (9th Cir. 1978).