Merwin filed for divorce in Los Angeles Superior Court, TMZ.com reported Tuesday.
Stating irreconcilable differences as the reason, Merwin filed papers seeking joint legal custody and physical custody of the couple's 16-year-old son, Samuel, as well as spousal support and payment for legal fees, the report said.
Busfield has starred in the TV dramas "Thirtysomething," "The West Wing" and "Studio 60 on the Sunset Strip."
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