The Mad Men actress, 28, filed divorce papers Monday in L.A. Superior Court, citing irreconcilable differences.
Moss lists June 26 as the date of their separation, according to the documents obtained by Entertainment Tonight, eight months after she married the Saturday Night Live funnyman.
A source previously told PEOPLE the couple's conflicting work schedules and long-distance relationship were causes for their split.
Armisen, 43, has since moved on with his SNL cast member Abby Elliot, 23. The two have been quietly dating and their relationship is still in "the early stages," says a source.