Can a physician assistant inject or prescribe in Missouri?

Short answer
Prescribing, yes — but only pursuant to a collaborative practice arrangement with a physician. On injecting, the cited rules do not settle it: the PA scope covers "routine therapeutic procedures" and trained tasks under a CPA, without naming injectables.

The scope of practice of a physician assistant shall consist only of the following services and procedures: taking patient histories; performing physical examinations of a patient; performing or assisting in the performance of routine office laboratory and patient screening procedures; performing routine therapeutic procedures; recording diagnostic impressions and evaluating situations calling for attention of a physician to institute treatment procedures; instructing and counseling patients regarding mental and physical health using procedures reviewed and approved by a collaborating physician; assisting the supervising physician in institutional settings; assisting in surgery; and performing such other tasks not prohibited by law under the collaborative practice arrangement with a licensed physician as the physician assistant has been trained and is proficient to perform.

Mo. Rev. Stat. §334.735.2 · verified Sep 3, 2026 · regulatory monitoring, not legal advice