19 CFR § 141.2 - Liability for duties on reimportation.
Dutiable merchandise imported and afterwards exported, even though duty thereon may have been paid on the first importation, is liable to duty on every subsequent importation into the Customs territory of the United States, but this does not apply to the following:
(a) Personal and household effects taken abroad by a resident of the United States and brought back on his return to this country (see § 148.31 of this chapter);
(b) Professional books, implements, instruments, and tools of trade, occupation, or employment taken abroad by an individual and brought back on his return to this country (see § 148.53 of this chapter);
(c) Automobiles and other vehicles taken abroad for noncommercial use (see § 148.32 of this chapter);
(d) Metal boxes, casks, barrels, carboys, bags, quicksilver flasks or bottles, metal drums, or other substantial outer containers exported from the United States empty and returned as usual containers or coverings of merchandise, or exported filled with products of the United States and returned empty or as the usual containers or coverings of merchandise (see § 10.7(b), (c), (d), and (e) of this chapter);
(e) Articles exported from the United States for repairs or alterations, which may be returned upon the payment of duty on the value of repairs or alterations at the rate or rates which would otherwise apply to the articles in their repaired or altered conditions (see § 10.8 of this chapter);
(f) Articles exported for exhibition under certain conditions (see §§ 10.66 and 10.67 of this chapter);
(g) Domestic animals taken abroad for temporary pasturage purposes and returned within 8 months (see § 10.74 of this chapter);
(h) Articles exported under lease to a foreign manufacturer (see § 10.108 of this chapter); or
(i) Any other reimported articles for which free entry is specifically provided.