The Diversity Immigrant Visa program is a United States congressionally-mandated lottery program for receiving a United States Permanent Resident Card. It is also known as the Green Card Lottery. The lottery is administered on an annual basis by the Department of State and conducted under the terms of Section 203(c) of the Immigration and Nationality Act (INA). Section 131 of the Immigration Act of 1990 (Pub. L. 101-649) amended INA 203 to provide for a new class of immigrants known as “diversity immigrants” (DV immigrants). The Act makes available 50,000 permanent resident visas annually to persons from countries with low rates of immigration to the United States.
Those born in any territory that has sent more than 50,000 immigrants to the United States in the previous five years are not eligible to receive a diversity visa. For DV-2010, natives of the following nations are ineligible: Brazil, Canada, China (mainland-born), Colombia, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, India, Jamaica, Mexico, Pakistan, Peru, Philippines, Poland, South Korea, United Kingdom (except Northern Ireland) and its dependent territories, and Vietnam . The entry period to apply for the DV-2010 was from October 2, 2008 to December 1, 2008.
The term 50,000 “immigrants” is partial and refers only to people who immigrated via the family-sponsored, employment, or immediate relatives of U.S. citizen categories, and does not include other categories such as refugees, asylum seekers, NACARA beneficiaries, or previous diversity immigrants. It is for this reason that Cuba, Ukraine, Russia, Iran, Ethiopia, Bangladesh and Nigeria are not on the ineligible list despite sending over 50,000 immigrants in the previous five years. 
The first program was DV-1995, and the following 13 countries were ineligible from the start: Canada, China (mainland), Dominican Republic, El Salvador, Haiti, India, Jamaica, Mexico, Philippines, South Korea, Taiwan, United Kingdom (except Northern Ireland) and its dependent territories, and Vietnam.
Changes to the list of countries over the years include the following:
* DV-1996: Colombia now ineligible.
* DV-1998: Poland now ineligible.
* DV-2002: Poland and Taiwan now eligible, Pakistan ineligible.
* DV-2004: East Timor added, eligible.
* DV-2005: Russia now ineligible.
* DV-2007: Poland again ineligible.
* DV-2008: Brazil and Peru now ineligible; Serbia and Montenegro listed separately, both eligible.
* DV-2009: Ecuador and Guatemala now ineligible.
* DV-2010: Russia now eligible; Kosovo added, eligible.
* DV-2011: No changes expected, according to 2008 immigration statistics from the Department of Homeland Security.
The large number of changes for DV-2002 was due to a three-year gap between the publication of the 1998 and 1999 immigration statistics. In other words, DV-2001 was still using the statistics from the five-year period from 1994 to 1998 to determine country eligibility. As immigration has increased, the number of ineligible countries has risen, from 13 for DV-1995 to 19 now. Taiwan is the only country which was ineligible in 1995 but eligible now due to decreasing immigration.
Russia fell below the ineligibility limit for DV-2010  due to a combination of a sharp dropoff in adoptions (from 5,878 in 2004 to 2,301 in 2007) and the unusual bureaucratic quirk of large numbers of Russian immigrants being allocated to “Soviet Union (former)” rather than Russia in 2006 and 2007.