The Don't Ask, Don't Tell Repeal Act of 2010 (H.R. 2965, S. 4023) is a landmark United States federal statute enacted in December 2010 that established a process for ending the Don't ask, don't tell (DADT) policy (10 U.S.C. § 654), thus allowing gays, lesbians, and bisexuals to serve openly in the United States Armed Forces. It ended the policy in place since 1993 that allowed them to serve only if they kept their sexual orientation secret and the military did not learn of their sexual orientation.
The Act established a process for ending the "Don't ask, don't tell" policy. According to the Congressional Research Service, the Act:
Provided for repeal of the current Department of Defense (DOD) policy concerning homosexuality in the Armed Forces, to be effective 60 days after the Secretary of Defense has received DOD's comprehensive review on the implementation of such repeal, and the President, Secretary, and Chairman of the Joint Chiefs of Staff (JCS) certify to the congressional defense committees that they have considered the report and proposed plan of action, that DOD has prepared the necessary policies and regulations to exercise the discretion provided by such repeal, and that implementation of such policies and regulations is consistent with the standards of military readiness and effectiveness, unit cohesion, and military recruiting and retention.
The Act did not ban discrimination on the basis of sexual orientation in the military, as provided for in the proposed Military Readiness Enhancement Act.
President Barack Obama, Defense Secretary Leon Panetta, and Chairman of the Joint Chiefs of Staff Admiral Mike Mullen provided the certification required by the Act to Congress on July 22, 2011. Implementation of repeal was completed 60 days later, so that DADT was no longer policy as of September 20, 2011.
This summary is from Wikipedia.