Section was formerly classified to section 3766a of Title 42, The Public Health and Welfare, prior to editorial reclassification and renumbering as this section.

A prior section 521 of Pub. L. 90–351, title I, June 19, 1968, 82 Stat. 208; Pub. L. 91–644, title I, § 7(9), Jan. 2, 1971, 84 Stat. 1888; Pub. L. 93–83, § 2, Aug. 6, 1973, 87 Stat. 215; Pub. L. 94–503, title I, §§ 127, 128(a), Oct. 15, 1976, 90 Stat. 2424, related to recordkeeping requirements, prior to the general amendment of title I of Pub. L. 90–351 by Pub. L. 96–157.

2016—Subsec. (c). Pub. L. 114–155 added subsec. (c).