Mo. Rev. Stat. § 330.090
Any person licensed to practice podiatric medicine in this state who has retired or may hereafter retire from such practice shall not be required to register as required by this chapter, provided such person shall file with the board an affidavit which states the date on which the person retired from the practice of podiatric medicine and such other facts as shall tend to verify the person's retirement as the board deems necessary; provided, however, that if such person thereafter reengage in the practice of podiatric medicine, the person shall reapply with the board as provided by section 330.030. The retired applicant shall and will be required to submit evidence of satisfactory completion of the applicable continuing education requirements as well as submitting the licensing, processing, and administration fees established by the board.
§ 330.090, RSMo