Medical Assistant Scope of Practice: Diagnosis and Prescribing Restrictions by State

Medical assistants (MAs) are unlicensed support personnel who perform administrative and clinical tasks under direct physician or licensed provider supervision. Their scope is narrowly defined by state law and generally excludes independent diagnosis, prescribing, or treatment planning.

Typical Permitted Clinical Tasks (Delegated, Supervised)

• Vital signs measurement and documentation
• Venipuncture and capillary puncture (where permitted by state)
• ECG acquisition
• Medication administration (oral, topical, intramuscular, subcutaneous) only per direct physician order and state allowance
• Wound care, dressing changes, suture/staple removal
• Patient education reinforcement (pre-approved materials)
• Specimen collection and processing

Explicitly Prohibited Functions

• Medical diagnosis or differential diagnosis
• Prescribing medications, controlled substances, or medical devices
• Independent interpretation of diagnostic tests
• Developing or modifying treatment plans
• Performing invasive procedures beyond delegated tasks (e.g., IV push medications, arterial puncture)
• Triage decisions requiring clinical judgment

State Variability

Some states (e.g., California, Washington) have detailed MA statutes with certified/registered categories and defined task lists. Others rely on general delegation rules under the Medical Practice Act. MAs must know their state's specific regulations.

Supervision Requirements

Direct supervision (physician on-site) is typically required for clinical tasks. The delegating provider retains legal responsibility for the MA's actions.

Distinction from Licensed Roles

Only licensed professionals—physicians (MD/DO), nurse practitioners (NPs), physician assistants (PAs), and in some states clinical nurse specialists (CNSs)—may diagnose and prescribe. MAs complement but do not substitute for these roles.