49 CFR § 1572.105 - Immigration status.
(1) A lawful permanent resident of the United States;
(2) A refugee admitted under 8 U.S.C. 1157;
(4) An alien in valid M-1 nonimmigrant status who is enrolled in the United States Merchant Marine Academy or a comparable State maritime academy. Such individuals may serve as unlicensed mariners on a documented vessel, regardless of their nationality, under 46 U.S.C. 8103.
(5) A nonimmigrant alien admitted under the Compact of Free Association between the United States and the Federated States of Micronesia, the United States and the Republic of the Marshall Islands, or the United States and Palau.
(6) An alien in lawful nonimmigrant status who has unrestricted authorization to work in the United States, except -
(i) An alien in valid S-5 (informant of criminal organization information) lawful nonimmigrant status;
(ii) An alien in valid S-6 (informant of terrorism information) lawful nonimmigrant status;
(iii) An alien in valid K-1 (Fianco(e)) lawful nonimmigrant status; or
(iv) An alien in valid K-2 (Minor child of Fianco(e)) lawful nonimmigrant status.
(i) B1/OCS Business Visitor/Outer Continental Shelf;
(ii) C-1/D Crewman Visa;
(iii) H-1B Special Occupations;
(iv) H-1B1 Free Trade Agreement;
(v) E-1 Treaty Trader;
(vi) E-3 Australian in Specialty Occupation;
(vii) L-1 Intracompany Executive Transfer;
(viii) O-1 Extraordinary Ability;
(ix) TN North American Free Trade Agreement;
(x) E-2 Treaty Investor; or
(d) If an employer terminates an applicant working under a nonimmigrant status listed in paragraph (a)(7) of this section, or the applicant otherwise ceases working for the employer, the employer must notify TSA within 5 business days and provide the TWIC to TSA if possible.
(f) To determine an applicant's immigration status, TSA will check relevant Federal databases and may perform other checks, including the validity of the applicant's alien registration number, social security number, or I-94 Arrival-Departure Form number.