Mo. Rev. Stat. § 334.044: Gratuitous medical services, summer camps, physician licensed in other state may perform, when.

Notwithstanding any other provision of law to the contrary, any qualified physician who is legally authorized to practice under the laws of another state may practice as a physician and surgeon in this state, without examination by the board or payment of any fee, if such practice consists solely of the provision of gratuitous medical services provided for a summer camp for a period of not more than fourteen days in any one calendar year.