Miller, the dean of California's congressional delegation, has been a leading Democratic party voice on education, labor and health care policy. He played a prominent role in developing President Barack Obama's signature health care overhaul, defended environmental regulations and fought against efforts to open up environmentally sensitive land to oil drilling and helped guide House Democrats on issues such as education funding and college affordability.
"I look forward to one last year in Congress fighting the good fight and then working in new venues on the issues that have inspired me," Miller said.
Miller, 68, was first elected in 1974 to his reliably Democratic San Francisco Bay area district and he has been a longtime adviser to Pelosi, serving on her leadership team while she was House speaker.
Pelosi said in a statement that Miller's "patriotism, wisdom and guidance have been especially valued, and he has been a close friend since my first days in the House."
The congressman's Capitol Hill home helped inspire Amazon's political comedy "Alpha House," a television series starring John Goodman about the lives of four U.S. senators who share a D.C. home while not in their home states.
Miller's roommates include Illinois Sen. Dick Durbin, the Senate's No. 2 Democrat, and Sen. Chuck Schumer, D-N.Y., who joked on Twitter: "Seeking roommate. 20 terms in the House & unmatched legislative record preferred.