PHP Certification in Washington: Rules, Costs, and Coverage

As of August 2026, Washington does not issue a separate license for a Partial Hospitalization Program (PHP). PHP is certified under the same "behavioral health outpatient intervention, assessment and treatment" category as intensive outpatient (IOP) and standard outpatient care, per WAC 246-341-0737. What makes PHP a distinct program is not a distinct license. It is hours of care (15 to 20 per week), clinical intensity, and, most consequentially for operators, who actually pays for it. This guide walks through the certification path, the Apple Health coverage rules that determine whether a Washington PHP is financially viable, and the steps to launch one in 2026.

What Is a PHP, and How Is It Different From IOP in Washington?

A Partial Hospitalization Program delivers structured, multidisciplinary behavioral health treatment, including individual, group, and family therapy, psychiatric medication management, medical monitoring, and often nutritional support, for clients who need more than outpatient therapy but not 24-hour inpatient or residential care. In Washington's managed-care billing framework, PHP and IOP are distinguished primarily by intensity:

• IOP. Roughly 9 to 12 hours of programming per week, delivered in at least three separate sessions.
• PHP. Roughly 15 to 20 hours per week, typically 4 to 5 hours a day, with a multidisciplinary team and closer medical oversight than IOP.

Both sit on the same continuum Oregon operators will recognize from OAR-based levels of care. See our companion breakdown of PHP, IOP, and outpatient levels of care in Oregon for the cross-state comparison. The clinical distinction matters because Washington's Medicaid program (Apple Health) treats PHP and IOP as separate, specifically-coded benefits rather than a single "intensive services" bucket, which is covered below.

Do You Need a Separate License to Open a PHP in Washington State?

No. If your agency already holds, or is applying for, a Behavioral Health Agency (BHA) license with certification for outpatient intervention, assessment and treatment services under Chapter 246-341 WAC, PHP falls within the scope of that same certification. There is no "PHP" line item on the Department of Health's list of certification categories, and no PHP-specific WAC section parallel to, say, opioid treatment program certification. For the full mechanics of the underlying BHA license, including the four licensing action types, deemed-status rules, and general application requirements, see our Washington BHA licensing guide, which functions as the hub for everything on this page.

That does not mean PHP is unregulated. WAC 246-341-0737 requires that agencies certified for intervention, assessment and treatment services provide individualized treatment planning, maintain an individual service plan for each client (with narrow exemptions for assessment-only or medication-management-only agencies), and, if the program serves involuntary or court-ordered clients, meet the noncompliance-reporting timelines in subsection (4) of the rule. Psychiatric medication management specifically must meet the service standards in WAC 246-341-0739. Practically, this means your PHP-specific policies and procedures, staffing plan, and documentation system need to demonstrate that a 15 to 20 hour-per-week, medically-monitored program meets the same certification standard the state applies to a once-a-week outpatient therapy caseload, which is a materially higher bar even though the underlying certification category is identical.

What Are the WAC 246-341 Certification Standards That Apply to PHP?

Because PHP is not separately defined, the compliance work is in mapping your PHP program design onto the outpatient certification standard and the general BHA administration rules that sit alongside it. In practice, surveyors and payers alike will expect to see:

• An individual service plan for every PHP client. Updated at a clinically appropriate interval given the intensity of care, not the annual or semi-annual cadence that might suffice for standard outpatient.
• Psychiatric medication management documentation that meets WAC 246-341-0739. PHP without a credentialed prescriber relationship and documented medication oversight will not pass survey or payer audit.
• A defensible level-of-care admission and continued-stay standard. Washington does not mandate a specific tool, but payers do. Coordinated Care of Washington, for example, uses LOCUS/CALOCUS composite scoring to authorize PHP. Building your clinical criteria around a recognized instrument (LOCUS, CALOCUS, or ASAM) from day one avoids a costly retrofit later. Our ASAM criteria and level-of-care program design guide walks through building defensible admission criteria for exactly this situation.
• Staffing that matches the acuity. A 15 to 20 hour-per-week multidisciplinary program needs a staffing and supervision plan that can survive both a DOH licensing survey and a payer audit. See our staffing ratios and clinical supervision guide for how to build one that holds up.

Does Apple Health (Washington Medicaid) Cover PHP? Who Actually Pays for It?

This is the question that determines whether a Washington PHP is a viable business line, and the answer is narrower than most operators assume. Washington's Apple Health coverage of IOP and PHP, effective January 1, 2024 following a 2022 legislative directive, mandates coverage for mental health IOP and PHP for individuals under age 21, under the federal Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit. Coverage for adults 21 and older is not a state mandate. Managed care organizations (MCOs) and behavioral health administrative services organizations (BH-ASOs) may voluntarily extend PHP/IOP coverage to adults, and several do, but it is a plan-level decision rather than a guaranteed benefit. Substance use disorder PHP and IOP are not covered under this same mandate; SUD clients can receive both mental health and SUD services concurrently when clinically indicated, but the mandate itself is mental-health-specific. Notably, ASAM level 2.5 PHP for SUD is not currently covered under Apple Health at all.

On the MCO side, coverage criteria are plan-specific and typically built around a standardized acuity tool. Community Health Plan of Washington (CHPW), for example, authorizes mental health PHP for adults using a LOCUS Adult composite score of 20 or higher (CALOCUS for clients under 21), requires documentation of psychiatric diagnosis, safety risk, functional impairment, and prior treatment history at referral, and excludes concurrent PHP for clients already enrolled in WISe, WA-PACT, New Journeys, or intensive residential treatment. Billing runs through HCPCS code H0035 for PHP and S9480 for IOP, both requiring the HK modifier for managed-care enrollees; hospital-based programs bill under EAPG methodology using revenue code 913 (PHP) or 905 (IOP) instead. Every MCO's authorization threshold and documentation requirements differ enough that a payer-by-payer contracting review, not just a DOH certification, should be part of any PHP launch plan.

How Much Does It Cost and How Long Does It Take to Add PHP Certification in Washington?

Because PHP shares its certification category with outpatient and IOP services, the fee structure depends on whether you are licensing a new agency or adding PHP to one you already operate.

Timeline follows the same review process as any BHA certification change. There is no statutory approval window, and total time to an active certification depends heavily on how complete the PHP-specific policies, staffing plan, and clinical criteria are on day one. Our Washington BHA licensing guide covers the full initial-review and processing timeline in detail; budget on the higher end of that range for a PHP addition, since surveyors will scrutinize the higher-acuity documentation more closely than a standard outpatient add-on.

How Do You Launch a PHP Program in Washington: Step by Step

The sequence that avoids rework:

• Confirm your base certification. You need an active or in-process BHA license with outpatient intervention, assessment and treatment certification before PHP can be added. There is no standalone PHP pathway.
• Build defensible admission and continued-stay criteria. Anchor PHP admission to a recognized acuity tool (LOCUS/CALOCUS or ASAM) before you contract with a single MCO, since every plan will ask for it.
• Design the staffing and medical-oversight model. A credentialed prescriber relationship, documented psychiatric medication management meeting WAC 246-341-0739, and a supervision structure sized to 15 to 20 hours per week of programming, not a once-weekly caseload.
• File the certification amendment (or include PHP in your initial application). Submit the $450 amendment with policies, staffing plan, and clinical criteria attached if adding to an existing license; include PHP in the outpatient service description if you are licensing new.
• Contract PHP separately with each MCO. Apple Health PHP coverage for adults is voluntary at the plan level. Molina, Coordinated Care, Community Health Plan of Washington, Wellpoint, and UnitedHealthcare Community Plan each set their own authorization criteria, so confirm coverage and rates plan by plan rather than assuming parity across your existing IOP contracts.
• Build the H0035/S9480 billing workflow before intake starts. Get modifier logic, revenue-code handling (if hospital-based), and units-of-service tracking built and tested before your first PHP client is admitted, not after the first denial.

Frequently Asked Questions

Does Washington require a separate license to operate a PHP?

No. PHP is certified under the same behavioral health outpatient intervention, assessment and treatment category (WAC 246-341-0737) that covers IOP and standard outpatient services. There is no distinct PHP license type.

How many hours per week does a Washington PHP need to provide?

Washington's managed-care billing framework treats PHP as roughly 15 to 20 hours of programming per week (typically 4 to 5 hours a day), compared to about 9 to 12 hours per week for IOP.

Does Apple Health cover PHP for adults in Washington?

Coverage for mental health PHP is mandated for individuals under 21 under EPSDT. For adults 21 and older, coverage is not state-mandated. Individual MCOs and BH-ASOs may voluntarily cover it, so confirm the benefit plan by plan. SUD PHP (ASAM 2.5) is not currently covered under Apple Health.

What billing codes are used for PHP and IOP in Washington?

PHP bills under HCPCS code H0035; IOP bills under S9480. Both require the HK modifier for managed-care enrollees. Hospital-based programs use EAPG methodology with revenue code 913 (PHP) or 905 (IOP) instead.

How much does it cost to add PHP certification to an existing Washington agency?

Adding PHP to an agency that already holds outpatient certification costs a flat $450 amendment fee. A brand-new agency instead pays the $2,250 application fee plus an outpatient certification fee tiered by projected annual service hours ($1,650 to $5,800 non-deemed, $830 to $2,900 with deemed/accredited status).

Do I need CARF or Joint Commission accreditation to run a PHP in Washington?

No, accreditation is not required to hold a Washington BHA certification. It is, however, financially relevant: deemed status from CARF or Joint Commission roughly halves the outpatient certification fee tier, and most MCOs weight accreditation favorably in PHP contracting decisions.

How Saint Health Group Helps You Launch a Washington PHP

Certifying a PHP in Washington is less about a single license application and more about proving, to DOH and separately to every MCO you contract with, that a 15 to 20 hour-per-week, medically-supervised program meets a standard the state wrote for outpatient therapy. Saint Health Group runs this end to end: we write the PHP-specific policies and procedures and individual service plan framework required under WAC 246-341-0737, build the LOCUS/CALOCUS or ASAM-anchored admission criteria your MCO contracts will require, design the staffing and psychiatric medication management model to meet WAC 246-341-0739, file the certification amendment or initial application, and run an on-site mock readiness review before DOH ever shows up. Because PHP viability lives or dies on payer coverage, we also handle the adjacent work most consultants leave out, including Apple Health MCO contracting and credentialing, H0035/S9480 billing workflow setup, and CARF or Joint Commission accreditation if deemed status is part of your fee strategy, as one accountable partner rather than a chain of separate vendors. Talk to us about launching a compliant, payer-ready PHP in Washington.