PMHNP · Washington
Collaborative Practice Agreement for Psychiatric Mental Health Nurse Practitioners in Washington
No. Psychiatric Mental Health Nurse Practitioners practice independently here. Washington does not require one.
Washington's Nurse Practice Act does not carve out a separate framework for psychiatric-mental-health NPs — PMHNPs are one of the NP population foci covered by the same RCW 18.79 full-practice-authority framework as general NPs. This entry exists for its own page/calculator weight, not a legal distinction.
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 — ARNPs 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
No PMHNP-specific schedule restriction found — psychiatric prescribing in practice skews toward Schedule II stimulants and Schedule IV benzodiazepines/hypnotics more heavily than general NP practice, reflected in calculatorWeights rather than a different legal limit.
Written agreement
Not required
Unconditional — same RCW 18.79 full-practice-authority framework as general NPs; no collaborating-physician agreement required.
Practice ownership (corporate practice of medicine)
Licensee-only ownership required — Same as the general `np` entry — Professional Service Corporation under RCW 18.100.050; Washington's ownership statute does not distinguish PMHNPs from other NP population foci.
Legal sources for these rules (2)
What a collaborating physician costs here
Typical monthly cost in Washington
$500 – $600
Estimate for one Psychiatric Mental Health Nurse Practitioner. 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.