Dr. Patricia Simmons is resigning from the University of Minnesota Board of Regents, three years before her term was to expire.

Simmons, a retired Mayo Clinic physician, has served on the board for 15 years. She previously announced plans to leave in 2015 before changing her mind and running for a third six-year term. This time, she says, she means it.

"At some point I think individuals and boards need to refresh, and this feels like the right time," she said.

Simmons, 67, said she decided to step down from the board now because it was becoming "much more challenging" to keep up with its demands. "To do it right, it's a large time commitment," she said.

Simmons said she wants more time to travel with her husband and spend with her grandchildren.

David McMillan, the board chairman, praised Simmons for her service, saying she provided "an invaluable perspective about board governance, history, the health sciences, and the university's impact on Minnesota that will be hard to replace."

Simmons said she's hopeful someone with medical experience will replace her on the 12-member board. "I would not resign without knowing that there were capable people available," she said. She said she plans to leave this spring, once the Legislature picks a replacement.