The couple made the decision together, their reps told People, which first had the news.
"Their primary focus and concern is for their son," the reps said on their behalf, additionally asking, as most celebs do, for privacy.
The two, both 42, met in the 1995 in the original production of "Rent" on Broadway. They married in 2003 and had a son, Walker, in September 2009.
As recently as October, Diggs said the couple were "doing good" as they hit their 10-year-anniversary, according to Us Weekly, which noted that rumors of infidelity had dogged them over the summer.
Those who don't make it to Broadway for shows like the original run of "