United States Secret Service Retirement Act of 2011 - Authorizes an individual who was appointed as an officer or member of the United States Secret Service Division or the United States Secret Service Uniformed Division during 1984, 1985, or 1986, who has actively performed duties other than clerical duties for 10 or more years directly related to the agency's protection mission, who is serving as an officer or member of the Secret Service Division or the Secret Service Uniformed Division, and who is participating in the Federal Employees' Retirement System (FERS) on the date of enactment of this Act, to file an election to be covered by the District of Columbia Police and Firefighters Retirement and Disability System in the same manner as officers and members appointed prior to 1984. Requires such individual to cover transition costs to such System by using amounts in his or her Thrift Savings Fund.