The 52-year-old, who spent 18 seasons as an on-court official, has been dealing with knee problems, according to Beck.
Alongside Dee Kantner, Palmer broke the NBA's gender barrier in 1997 and officiated 54 games that season:
She appeared in as many as 68 games in a season but saw that number decrease toward the end of her career because of injury issues.
In total, Palmer officiated 919 NBA games. She also became the first woman to oversee an NBA postseason game when she refereed Game 2 of a first-round Eastern Conference matchup between the Indiana Pacers and then-New Jersey Nets in 2006.
She officiated nine postseason games in six different seasons.
In 2013, former NBA executive vice president of operations Rod Thorn spoke to espnW's Johnette Howard about what set Palmer apart.
"She handles herself in the right way, she's bright and, after a lot of observation of her work and conversations with her, it just became clear that she was put together the right way to be a pioneer," he said. "Because that's what she and Dee were."
Palmer also became the first openly gay referee in NBA history, announcing in 2014, shortly after Jason Collins became the first openly gay player, that she would marry her longtime partner, Tanya Stine, per Dan Devine of Yahoo Sports.
Her success as an official in the league helped open up doors for other women. In 2014, Lauren Holtkamp became the third full-time female referee in NBA history. She has appeared in 115 games during her career.
Palmer will work as a manager in referee operations now that she is off the court, according to Beck.
Stats courtesy of Basketball-Reference.com.