What are the employment based immigrant categtories?

The law sets forth specific categories within the employment based immigrant quota:

CATEGORIES

Employment First Preference (E1)

Priority Workers receive 28.6 percent of the yearly worldwide limit. All Priority Workers must be the beneficiaries of an approved Form I- 140, Immigrant Petition for Foreign Worker, filed with USCIS. Within this preference there are three sub-groups:

Persons of extraordinary ability in the sciences, arts, education, business, or athletics. Applicants in this category must have extensive documentation showing sustained national or international acclaim and recognition in the field of expertise. Such applicants do not have to have a specific job offer so long as they are entering the U.S. to continue work in the field in which they have extraordinary ability. Such applicants can file their own petition with the USCIS, rather than through an employer;
Outstanding professors and researchers with at least three years experience in teaching or research, who are recognized internationally. No labor certification is required for this classification, but the prospective employer must provide a job offer and file a petition with the USCIS; and
Certain executives and managers who have been employed at least one of the three preceding years by the overseas affiliate, parent, subsidiary, or branch of the U.S. employer. The applicant must be coming to work in a managerial or executive capacity. No labor certification is required for this classification, but the prospective employer must provide a job offer and file a petition with the USCIS.

Employment Second Preference (E2)

Professionals Holding Advanced Degrees, or Persons of Exceptional Ability in the Arts, Sciences, or Business receive 28.6 percent of the yearly worldwide limit, plus any unused Employment First Preference visas. All Second Preference applicants must have a labor certification approved by the DOL, or Schedule A designation, or establish that they qualify for one of the shortage occupations in the Labor Market Information Pilot Program (later). A job offer is required and the U.S. employer must file a petition on behalf of the applicant. Aliens may apply for exemption from the job offer and labor certification if the exemption would be in the national interest, in which case the alien may file the petition, Form I-140, along with evidence of the national interest. There are two subgroups within this category:

Professionals holding an advanced degree (beyond a baccalaureate degree), or a baccalaureate degree and at least five years progressive experience in the profession; and
Persons with exceptional ability in the arts, sciences, or business. Exceptional ability means having a degree of expertise significantly above that ordinarily encountered within the field.

Employment Third Preference (E3)

Skilled Workers, Professionals Holding Baccalaureate Degrees and Other Workers receive 28.6 percent of the yearly worldwide limit, plus any unused Employment First and Second Preference visas. All Third Preference applicants require an approved I-140 petition filed by the prospective employer. All such workers require a labor certification, or Schedule A designation, or evidence that they qualify for one of the shortage occupations in the Labor Market Information Pilot Program. There are three subgroups within this category:

Skilled workers are persons capable of performing a job requiring at least two years'' training or experience;
Professionals with a baccalaureate degree are members of a profession with at least a university bachelor's degree; and
Other workers are those persons capable of filling positions requiring less than two years'' training or experience.

Employment Fourth Preference (E4)

Special Immigrants receive 7.1 percent of the yearly worldwide limit. All such applicants must be the beneficiary of an approved I-360, Petition for Special Immigrant, except overseas employees of the U.S. Government who must use Form DS-1884. Certain spouses and children may accompany or follow-to-join the principal special immigrant. Different types of special immigrants provided for under immigrant law are listed below:

Broadcaster in the U.S. employed by the International Broadcasting Bureau of the Broadcasting Board of Governors or a grantee of such organization;
Minister of Religion;
Certain Employees or Former Employees of the U.S. Government Abroad;
Employee of the Mission in Hong Kong;
Certain Former Employees of the Panama Canal Company or Canal Zone Government;
Certain Former Employees of the U.S. Government in the Panama Canal Zone;
Certain Former Employees of the Panama Canal Company or Canal Zone Government on April 1, 1979;
A. Interpreters and translators of Iraqi or Afghan nationality who have worked directly with the United States armed forces or under Chief of Mission authority as a translator or interpreter for a period of at least 12 months and meet requirements. This classification has an annual numeric limitation of 500 visas through FY 08.
B. Iraqis who have provided faithful and valuable service while employed by or on behalf of the U.S. government in Iraq for not less than one year after March 20, 2003, and have experienced an ongoing serious threat as a consequence of that employment. This provision was signed into law in January 2008, creating 5,000 special immigrant visas each year for the next five years. The Department of State and the Department of Homeland Security are establishing regulations and procedures to permit applications under the new legislation to begin as soon as possible.
Certain Foreign Medical Graduates (Adjustments Only);
Certain Retired International Organization employees;
Certain Spouses of a deceased International Organization Employee;
Juvenile Court Dependent (no family member derivatives);
Alien Recruited Outside of the United States Who Has Served or is Enlisted to Serve in the U.S. Armed Forces;
Certain retired NATO-6 civilians;
Certain surviving spouses of deceased NATO-6 civilian employees;
Alien beneficiary of a petition or labor certification application filed prior to Sept. 11, 2001, if the petition or application was rendered void due to a terrorist act of Sept. 11, 2001;
Certain Religious Workers.

Employment Fifth Preference (E5)

Employment Creation Investors receive 7.1 percent of the yearly worldwide limit. All applicants must file a Form I-526, Immigrant Petition by Alien Entrepreneur with USCIS. To qualify, an alien must invest between U.S. $500,000 and $1,000,000, depending on the employment rate in the geographical area, in a commercial enterprise in the United States which creates at least 10 new full-time jobs for U.S. citizens, permanent resident aliens, or other lawful immigrants, not including the investor and his or her family.