Mo. Rev. Stat. § 217.365: Offenders not to carry money, exceptions, violations, treated as contraband.

No offender while confined in any correctional center of the department, except those offenders so authorized by the chief administrative officer of a particular center, shall be permitted to have on his person, in his cell, or in his immediate possession, any money or legal tender of any description. Such money or legal tender shall be considered contraband under the rules and regulations of the department. Such contraband shall be confiscated and deposited in the inmate canteen fund and expended pursuant to section 217.195.