Not all aliens who were "admitted" or "paroled" can adjust status. The following classes are ineligible to adjust.

Ø      A crewmen member admitted in the D nonimmigrant category. An alien who, at the time of arrival, was serving in any capacity on board a vessel or aircraft or were destined to join a vessel or aircraft in the United States to serve in such a capacity is barred from adjustment of status;

Ø      An alien admitted in transit without a visa (TWOV) through the U.S. to another country. Aliens who are in immediate and continuous transit through the United States to a foreign destination, in accordance with the terms of an agreement entered into between the transportation line and USCIS, are not eligible for adjustment of status.

Ø      An alien admitted in the J category who is subject to the two-year home country residence requirement and has not fulfilled the requirement or received a waiver of is is barred from AOS;

Ø      An alien (other than an immediate relative) who was admitted as a nonimmigrant visitor without a visa under section 212(l) [visa waiver for B-1/B-2 admission to Guam] or section 217 [visa waiver program] is barred from AOS;

Ø      A fiancé or fiancée of a U.S. citizen admitted in K category. The aliens may only be adjusted to permanent residence only if the adjustment is a result of the United States citizen who filed the petition to classify him or her as a K-1;

Ø      Aliens who have ever engaged in unauthorized employment, who are not in lawful status at the time of filing of the adjustment application or who have failed to continuously maintain status since their entry into the United States are barred from adjustment of status. However, this statutory bar does not apply to immediate relatives of United States citizens or certain special immigrants;

Ø      Aliens who enter into marriages during pendency of administrative or judicial proceedings are not eligible to AOS. Any alien who marries on or after November 10, 1986, and while the alien was in exclusion, deportation, or removal proceedings, or judicial proceedings relating thereto, is barred from adjustment of status. In addition, the INA prohibits approval of a petition granting immediate relative or preference status based on the marriage until the alien has resided outside the United States for two (2) years after the marriage. Once that foreign residence requirement has been met, the restriction against adjustment does not apply. The USCIS regulations provide for lifting the restriction if the alien is found not deportable or excludable, or if the Service cancels the order to show cause.