Sen. Richard Shelby, the Alabama Republican who was first elected to the U.S. Senate as a Democrat in 1986, will not seek a seventh term in office in 2022.
"For everything, there is a season," he said in a statement.
"I am grateful to the people of Alabama who have put their trust in me for more than forty years," he said. "I have been fortunate to serve in the U.S. Senate longer than any other Alabamian."
Shelby, 86, switched parties in 1994 and has chaired the Senate Appropriations, Banking, Intelligence and Rules committees.
"In these positions of leadership, I have strived to influence legislation that will have a lasting impact – creating the conditions for growth and opportunity," he said.
His retirement will open a Senate seat in a safe Republican state. His Alabama colleague, Sen. Tommy Tuberville, beat Democratic incumbent Doug Jones in the 2020 election by more than 20 percentage points.
Shelby is the fourth GOP senator who won't seek reelection in 2022, along with Pennsylvania's Pat Toomey, Ohio's Rob Portman and North Carolina's Richard Burr, who announced in 2016 that this term would be his last.
Shelby is currently the ranking member on the Senate Appropriations Committee, which he chaired until the recent election in which Democrats took control of the Senate. He was elected to the U.S. Senate following four terms in the House and eight years in the Alabama state Legislature.