The 52-year-old won two Emmys for her role as attorney Alicia Florrick on the original hit drama, which ran for seven seasons until 2016, and producers subsequently launched a follow-up show, called "The Good Fight", focusing on Christine Baranski's legal eagle Diane Lockhart.
"The Good Fight" is currently in its third season on streaming platform CBS All Access, and Margulies reveals she was asked to return as Florrick for a three-episode arc, but she walked away from negotiations after network bosses allegedly wanted her to take a pay cut and receive the guest character rate.
The star explains she "really wanted to do it," but "the deal didn't happen".
"To be perfectly honest, I was shocked," she confessed to Deadline.com. "I was more surprised than hurt. I thought, 'What are you worth?'."
"I'm not a guest star; I started the whole thing with The Good Wife," Margulies continued, insisting no male lead would ever be treated in the same way.
As a result of the snub, Margulies has no interest in ever stepping back into Florrick's shoes: "If you are worthless, if you are not valued for your work, than what's the point?" she asked.
Representatives for CBS have yet to respond to the actress' comments.