U.S. Rep. Barney Frank, D-Mass., will announce the end of his two-decade long stint in Congress on Monday afternoon, backing down from a re-election run in 2012.

The 16-term lawmaker plans to announce the decision at a press conference in Newtown, Mass., Monday, followed by a second discussion in Washington, D.C. on Tuesday.

Frank was first elected in 1980, and is the ranking Democrat on the House Financial Services Committee. He gained recent attention with the eponymous Dodd-Frank law, which increases regulations on the financial industry. He's also an outspoken advocate of gay rights, and one of the first openly gay men to serve in Congress.