INA: ACT 101 - DEFINITIONS :
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(15) The term "immigrant" means every alien except an alien who is within one of the following classes of nonimmigrant aliens
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(H) an alien (i) 3a/ 3b/ (b) subject to section 212(j)(2), who is coming temporarily to the United States to perform services (other than services described in subclause (a) during the period in which such subclause applies and other than services described in subclause (ii)(a) or in subparagraph (O) or (P)) in a specialty occupation described in section 214(i)(1) or as a fashion model, who meets the requirements for the occupation specified in section 214(i)(2) or, in the case of a fashion model, is of distinguished merit and ability, and with respect to whom the Secretary of Labor determines and certifies to the Attorney General that the intending employer has filed with the Secretary an application under section 3b/ 212(n)(1), or (b1) who is entitled to enter the United States under and in pursuance of the provisions of an agreement listed in section 214(g)(8)(A), who is engaged in a specialty occupation described in section 214(i)(3), and with respect to whom the Secretary of Labor determines and certifies to the Secretary of Homeland Security and the Secretary of State that the intending employer has filed with the Secretary of Labor an attestation under section 212(t)(1), or (c) 3b/ who is coming temporarily to the United States to perform services as a registered nurse, who meets the qualifications described in section 212(m)(1), and with respect to whom the Secretary of Labor determines and certifies to the Attorney General that an unexpired attestation is on file and in effect under section 212(m)(2) for the facility (as defined in section 212(m)(6)) for which the alien will perform the services; or
(ii)(a) having a residence in a foreign country which he has no intention of abandoning who is coming temporarily to the United States to perform agricultural labor or services, as defined by the Secretary of Labor in regulations and including agricultural labor defined in section 3121(g) of the Internal Revenue Code of 1954 and agriculture as defined in section 3(f) of the Fair Labor Standards Act of 1938 (29 U.S.C. 203(f)), of a temporary or seasonal nature, or (b) having a residence in a foreign country which he has no intention of abandoning who is coming temporarily to the United States to perform other temporary service or labor if unemployed persons capable of performing such service or labor cannot be found in this country, but this clause shall not apply to graduates of medical schools coming to the United States to perform services as members of the medical profession; or
(iii) having a residence in a foreign country which he has no intention of abandoning who is coming temporarily to the United States as a trainee, other than to receive graduate medical education or training, in a training program that is not designed primarily to provide productive employment; and the alien spouse and minor children of any such alien specified in this paragraph if accompanying him or following to join him;