9/11 Memorial and Museum Act This bill directs the Department of Homeland Security (DHS) to award to the official organization that operates the National September 11 Memorial & Museum a one-time grant to be used solely for the purposes of the operation, security, and maintenance of the memorial and museum. As a condition on receipt of the grant, the organization must provide for free admission to all facilities and museums associated with the memorial and museum for active and retired members of the Armed Forces, individuals who were registered first responders to the terrorist attacks of September 11, 2001, and family members of victims of such attacks; provide for dedicated free admission hours for the general public at least once a week; and allow for annual federal audits of its financial statements.