Longtime California Rep. Grace Napolitano announced Saturday that she is retiring from Congress at the end of her current term.

"I am incredibly grateful for the people of the San Gabriel Valley and the people of Southeastern Los Angeles County for the trust they have bestowed in me to represent them for a quarter century," the Democrat said in a statement.

A Texas native, Napolitano is currently serving her 13th term in the House, representing a majority-Latino district in the Los Angeles area. She was first elected to the chamber in 1998 after six years in the California State Assembly and a stint as the mayor of Norwalk, California, where she also served on the city council.

At 86, Napolitano is the oldest member of the House. New Jersey Democrat Bill Pascrell is also 86, but a month younger than Napolitano.

While control of the House will be up for grabs in 2024, Napolitano's 31st Congressional District will likely remain noncompetitive for Republicans. She won reelection in 2022 with 59.5% of the vote in a redrawn district that Joe Biden would have carried by 31 points in 2020.

Napolitano has made mental health care a priority over her tenure in Washington and serves as a co-chair of the Congressional Mental Health Caucus.

"When I came to the federal government, mental health issues were not spoken of, families kept them secret, and internal turmoil simmered in our children, parents, and adults. I am very glad to say we have reduced the stigma of mental health, locally and nationally. We have made it acceptable for people to talk about their mental health and get treatment," she said Saturday.

Napolitano is a senior member of the House Natural Resources Committee and the House Transportation and Infrastructure panel. She is also a member of the Congressional Progressive Caucus and previously served as chairwoman of the Congressional Hispanic Caucus.

"When I came to Congress in 1999, there were 18 members of the Hispanic Caucus, and now there are 42 members," she said.

Napolitano is the ninth Democrat and 12th House member so far to announce they won't run for reelection in 2024. And she's not the only California Democrat leaving the chamber at the end of the term. Three of her colleagues -- Reps. Adam Schiff, Katie Porter and Barbara Lee -- are vacating their districts to seek the open Senate seat being vacated by retiring Democratic Sen. Dianne Feinstein.