"I am done," Heigl told the magazine. "We just finalized our agreement. Everyone had been working really hard to find an amicable and gracious way of letting go and moving on. It's sad but it's what I wanted."
The actress said she asked to be released from her contract 18 months early because of family issues and the show's producers agreed, meaning the Jan. 21 episode was her last.
"I started a family and it changed everything for me," she explained. "It changed my desire to work full-time."
Heigl recently adopted a baby girl.
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