"Serving my constituents in Congress has been the single most distinguished honor of my life,'' the 80-year-old Roybal-Allard, a Democrat, said in a statement.
"Over my many years of public service, I have always strived to do that which is best to help improve my community and my country. After 30 years in the House of Representatives, the time has come for me to spend more time with my family. Therefore, I have decided not to seek reelection.''
Roybal-Allard's 40th Congressional District includes Bell, Bell Gardens, Commerce, Cudahy, Downey, Huntington Park, Maywood, Paramount, Vernon and portions of Bellflower, East Los Angeles, Florence-Firestone and South Los Angeles.
She was the first Latina to serve on the House Appropriations Committee and to chair an Appropriations Subcommittee.
Long Beach Mayor Robert Garcia praised the veteran representative's work.
"Congresswoman Roybal-Allard is a trailblazer and has been a fearless advocate for Los Angeles and the Southeast cities,'' Garcia said. "She has been an incredible national leader on immigration, equality and for working families. I am tremendously grateful for her leadership and service to our country and our community.''
Garcia announced last week that he would run for Congress in 2022, though new districts have yet to be finalized.
Roybal-Allard did not disclose specific plans for the future, but said she would continue to support her district, which includes South and East Los Angeles.
"While I will not be seeking re-election in 2022, I look forward to continue to work for the people of my district in the new year and long after I leave public office,'' she said.
She did not mention redistricting as a factor in her decision, though she told the Los Angeles Times in November that she had concerns the new maps would dilute the power of Latino voters she currently represents.
"I am aware of the current draft map and I have concerns about the protections of Voting Rights [Act] districts and in particular the diluting of the vote in our Latino communities,'' she said, while urging the commission to address those issues before finalizing the districts.
Roybal-Allard was one of three House Democrats to announce Monday they would not run again, bringing the total number of retirements before the midterm elections to 23, according to the Washington Post.
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