CNM · Washington
Collaborative Practice Agreement for Certified Nurse-Midwives in Washington
No. Certified Nurse-Midwives practice independently here. Washington does not require one.
CNMs are one of Washington's four ARNP roles under RCW 18.79 — licensed independent practitioners with no physician supervision or agreement required.
What the collaboration must look like
The rules the physician relationship has to follow. Each fact comes from the statute or board rule listed under sources.
Proximity
No proximity requirement
No physician-oversight relationship exists — ARNP-CNMs are licensed independent practitioners.
Supervision ratio
Not codified — no cap on file
Chart review
Not codified — left to the agreement
Meeting cadence
Not codified — left to the agreement
Prescriptive authority
Covered by the practice agreement · controlled substances permitted
Schedule II-V upon Board of Nursing prescriptive-authority approval (RCW 18.79.240); Schedule I excluded.
Written agreement
Not required
Unconditional — Washington does not require a physician agreement for CNMs licensed as ARNPs.
Practice ownership (corporate practice of medicine)
Licensee-only ownership required — Professional Service Corporation under RCW 18.100.050 — CNMs are among the 12 enumerated health professions eligible to co-own a multi-discipline PSC; non-licensees may not hold equity.
Legal sources for these rules (1)
What a collaborating physician costs here
Typical monthly cost in Washington
$500 – $600
Estimate for one Certified Nurse-Midwife. Standard-tier state.
About Washington's rules
Washington is a full-independence state for ALL FOUR ARNP roles (NP, CRNA, CNM, CNS) under RCW 18.79, not just NPs — confirmed current via WAC 246-840-300/420 and Board of Nursing guidance. PAs are separate: HB 2041 (eff. Jan. 1, 2025) replaced supervision-only with a 4,000-hour supervision→collaboration tier (RCW 18.71A.120) with no numeric ratio cap.
Other clinicians in Washington: see the state overview.