Mark Twain Commemorative Coin Act - Directs the Secretary of the Treasury to mint and issue $5 gold coins and $1 silver coins emblematic of the life and legacy of Mark Twain.
Limits issuance of such coins to calendar year 2013.
Requires specified surcharges in the sale of such coins, which shall be promptly paid, in specified percentages, to: (1) the Mark Twain House & Museum in Hartford, Connecticut, to support the continued restoration of the house and grounds, and ensure continuing growth and innovation in museum programming to research, promote, and educate on the legacy of Mark Twain; (2) the Mark Twain Project at the Bancroft Library of University of California, Berkeley, California, to support programs to study and promote Mark Twain's legacy; (3) the Center for Mark Twain Studies at Elmira College, New York, for the same purposes; and (4) the Mark Twain Boyhood Home and Museum in Hannibal, Missouri, to preserve historical sites related to Mark Twain and help support study and promotion programs.