The head of Hawaii Medical Service Association is retiring at year’s end after a 43-year career at the state’s largest health insurer.

HMSA CEO Michael Gold will be succeeded by Michael Stollar, the current president and chief operating officer, on Jan. 1.

Gold joined HMSA in his 20s after a stint in the U.S. Air Force and attending the University of Hawaii.

“I thought I’d be here only for a short time, but I stayed because of the commitment people at HMSA have for helping others,” Gold said in a news release. “Throughout my career, I’ve been inspired by the social workers who founded HMSA to help their family, friends, and neighbors.”

He most recently helped HMSA shift to a new insurance payment model for Hawaii doctors and medical providers and led the company through the rollout of the federal Affordable Care Act, or Obamacare, which expanded the number of insured covered by the health plan. He also led HMSA’s preventive programs to encourage members to eat better and exercise more and take control of their health.

HMSA has more than 732,000 members.

Stollar, who has worked at HMSA for more than 30 years, said: “My job is to ensure that we continue working with every stakeholder to build a community system of health that is safe, affordable, accessible, and delivers the kinds of health and well-being outcomes that Hawaii’s people deserve. We will constantly work to make it easy for people to be meaningfully engaged in their own health.”