Entrance into the site is free. Visits inside the Main House are also free;however, tickets (time-specific "calling cards") are required, and are available at the Visitor Center. Advanced reservations are strongly recommended for groups of 10 or more. Call (314)842-1867 to make reservations, as well as for additional information and specific details about group program offerings.
Although Ulysses S. Grant National Historic Site is a fee-free park, you can purchase the America the Beautiful Annual and Senior Passes. Access, and Military passes are also available at the site. The Access, Military and Senior passes require verification of disability, active duty status or age. (You must be at least 62 to purchase the Senior pass.)
Further information about the passes can be found on the America the Beautiful pass webpage.