Described as a dark comedy in the tradition of "Weeds," the series, which doesn't have a name yet, will be shot in New York. Showtime is hoping for a premiere sometime late this year.
Falco was nominated for a best actress Emmy six times for her role as the mob wife in HBO's "The Sopranos," and won three times.
"My time on `The Sopranos' was so rich and full," she said. "The challenge has been finding something else that would excite me. This character and the writing are truly thrilling."