The new contract with Lionsgate TV and AMC will make Hamm one of the highest-paid actors on cable television, according to Deadline.
Hamm's agreement comes several months after AMC renewed Mad Men for two more seasons — Seasons 5 and 6 — and then locked in creator and showrunner Matthew Weiner for those two seasons (with the option for a third) in a deal estimated to be worth $30 million.
Since Hamm's deal carries him through the next three seasons, it's looking likely that Mad Men will run through Season 7. This works out quite nicely since Weiner told the media earlier this year that he plans for the critically acclaimed drama to end after three more seasons.
Season 5 is expected to air in early 2012, with Hamm, 40, set to direct the premiere episode.
Hamm has earned a Globe Globe award and three Emmy nominations for his performance as '60s advertising man Don Draper. He most recently appeared in the big screen comedy Bridesmaids.