Medicare coverage of IOP and PHP: which programs can bill, and what it takes

The short answer: Medicare pays for PHP only through hospital outpatient departments and certified community mental health centers (CMHCs), and for IOP through those two plus federally qualified health centers (FQHCs), rural health clinics (RHCs) and, as a weekly add-on for opioid use disorder, opioid treatment programs (OTPs). A freestanding program licensed only as a Texas chemical dependency treatment facility isn't one of these provider types, so it can't bill Medicare for a program day, though its Medicare-enrolled clinicians can bill their own services. For 2026, Medicare's national per diem for a hospital program is about $322 for a day with three services and about $422 for four or more; CMHCs get about 40% of that. A physician must certify the need for at least 9 hours a week of IOP or 20 hours a week of PHP.

1. Who can bill Medicare for IOP and PHP

CMS's 2024 outpatient rule created the Medicare IOP benefit from January 1, 2024, implementing the Consolidated Appropriations Act, 2023. It defines IOP as a distinct, organized outpatient program of psychiatric services for people with an acute mental illness, including substance use disorders.

Provider type	PHP	IOP	How it's paid
Hospital outpatient department	Yes	Yes, since 2024	OPPS per diem, one rate for 3-service days and one for 4+ (APCs 5861–5862 for IOP, 5863–5864 for PHP)
Community mental health center (CMHC)	Yes	Yes, since 2024	OPPS per diem at CMHC rates, the same 3 and 4+ tiers
FQHC	No	Yes, since 2024	The lesser of charges or the hospital 3-service per diem
Rural health clinic	No	Yes, since 2024	The hospital 3-service per diem amount
Opioid treatment program	No	For opioid use disorder, since 2024	Weekly add-on HCPCS G0137 on top of the OTP bundle
Freestanding IOP or PHP (Texas CDTF, private clinic)	No	No	Not a Medicare provider type for program days

For OTPs, CMS's billing guidance sets the threshold for G0137 at a minimum of nine services over seven contiguous days, with a physician or qualifying practitioner certifying the need for at least 9 hours a week (CMS OTP billing and payment). Starting an OTP is its own project; see how to start an opioid treatment program in Texas.

2. Why a freestanding program can't bill Medicare for a program day

Medicare pays program days to provider types defined in federal law, enrolled and certified as institutions. A Texas CDTF license is a state license; it doesn't make the program a hospital, a CMHC or a health center in Medicare's eyes. Three things follow:

• No per diem. You can't bill H0015, S9480, S0201 or the revenue-code equivalents to Medicare for a client's program day.
• Clinicians can bill their own services. Physicians, NPs, psychologists, LCSWs and, since January 1, 2024, LPCs (as mental health counselors) and LMFTs can enroll in Medicare and bill individual services such as psychotherapy or psychiatric visits. LCDCs generally can't bill Medicare on their own. See Medicare enrollment for LPCs and LMFTs.
• Plan the payer mix without Medicare program revenue. In the roadmap we build for every program client, "find out whether Medicare can pay your program" comes right after the program model is chosen, before the budget. The IOP break-even calculator lets you model it.

Mental-health-only programs face the same Medicare rule plus a licensing question of their own; see licensing a mental health IOP or PHP in Texas.

3. The paths to Medicare program billing

Path	What it involves	Fits
Become a CMHC	Meet the federal CMHC definition and conditions of participation, enroll with your MAC, pass an initial certification survey. See the next section.	Mental health organizations already providing the full range of core services, with a large non-Medicare caseload
Run the program as a hospital department	The hospital bills under its own Medicare enrollment; an outside operator may manage it under contract. Off-campus locations raise provider-based questions (42 CFR 413.65) for the hospital's counsel.	Programs with a hospital partner that wants an outpatient psychiatric line
FQHC or RHC IOP	An existing health center adds IOP within its scope and certification	Health centers, not new programs
OTP IOP add-on	A certified OTP furnishes intensive services for opioid use disorder and bills G0137 weekly	Existing OTPs
No program billing	Bill enrolled clinicians' services; refer Medicare clients needing program care to a hospital or CMHC program	Most freestanding Texas IOPs

Any arrangement with a hospital, a management company or a referral partner needs a health-care attorney: the federal Anti-Kickback Statute applies to Medicare business, and EKRA and the Texas Patient Solicitation Act apply to referrals for every payer (see patient brokering laws).

4. What a CMHC has to be

"Community mental health center" is a federal Medicare term. It isn't the same as the local mental health authorities Texas calls community centers under Health and Safety Code chapter 534, though a community center could also seek Medicare CMHC certification.

The definition: four core services

Under 42 CFR 410.2, a CMHC provides:

1. Outpatient services, including specialized services for children, the elderly, people with serious and persistent mental illness, and residents of its service area discharged from inpatient mental health treatment.
2. 24-hour-a-day emergency care services.
3. Day treatment or other partial hospitalization services, or psychosocial rehabilitation services.
4. Screening for patients being considered for admission to state mental health facilities, to determine whether admission is appropriate.

A substance-use-only IOP doesn't look like this. It's a full community mental health organization.

The 40 percent rule

A CMHC must provide at least 40 percent of its items and services to people who aren't eligible for Medicare (42 CFR 485.918(b)(1)), measured by client counts. A newly enrolling or revalidating CMHC submits a certification from an independent entity, such as an accountant, that it reviewed the client data and the CMHC meets the requirement. The MAC checks it before CMS schedules the initial certification survey (CMS transmittal).

The conditions of participation

The CMHC conditions of participation are at 42 CFR 485.904 through 485.918, with CMS's interpretive guidance on its CMHC page. They cover personnel qualifications, client rights, admission, initial evaluation and comprehensive assessment, the interdisciplinary treatment team and active treatment plan, quality assessment and performance improvement, and organization and governance, including how PHP and IOP services are run (485.918).

Enrolling

• Enroll as an institutional provider with your Medicare administrative contractor. In Texas that's Novitas Solutions (Jurisdiction H). Noridian's CMHC enrollment page lays out the steps a MAC expects.
• Pass the initial certification survey against the conditions of participation.
• Have the 40 percent certification, the policies, the staff and the client mix in place before you apply. CMHC certification is a long project, not a way to open faster.

5. Patient eligibility and physician certification

Rule	PHP	IOP
Who it's for	A patient who would otherwise need inpatient psychiatric care	A patient with an acute mental illness, including SUD, who needs more than routine outpatient care
Minimum hours	20 hours a week of therapeutic services	9 hours a week
Certification	A physician certifies the need for PHP and the hours	A physician certifies the need for at least 9 hours a week
Recertification	First as of the 18th day of PHP services, then at least every 30 days	No less often than every other month
Plan of care	Individualized, established and periodically reviewed by a physician	Individualized, established and periodically reviewed by a physician

A PHP recertification is signed by a physician treating the patient and addresses the patient's response to treatment, the psychiatric symptoms that still put them at risk of hospitalization, and treatment goals toward discharge (42 CFR 424.24; Medicare Benefit Policy Manual, chapter 6). CMS declined in the 2024 rule to change the 18th-day timing for PHP.

6. How the 2026 per diem works

Medicare pays PHP and IOP a daily rate under the hospital outpatient prospective payment system (OPPS), with one rate for days with three services and a higher one for days with four or more. Since 2024 the IOP and PHP rates have been the same within each provider type and tier. CMS set the 2026 amounts in the CY 2026 OPPS final rule (CMS-1834-FC), issued November 21, 2025 and published November 25, 2025 (Federal Register; CMS fact sheet).

Provider type	3-service day	4-or-more-service day
Hospital outpatient department (PHP or IOP)	The hospital 3-service rate	The hospital 4-or-more rate
CMHC (PHP or IOP)	About 40% of the hospital rate	About 40% of the hospital rate
FQHC or RHC (IOP only)	Based on the hospital 3-service amount	Not applicable

We don't print the dollar amounts: published summaries of the 2026 rule disagree by a few dollars (some quote CMS's cost figures, some the payment rates), and the exact rate comes from Addendum A of the current OPPS rule, by APC. Our IOP reimbursement guide shows how to look it up step by step, and the PHP reimbursement guide covers the PHP APCs. Rates are national, before the wage-index adjustment, and the patient owes Part B cost-sharing.

• Why CMHCs get about 40%. For 2026, CMS set CMHC PHP and IOP costs at 40 percent of the hospital-based costs, which is why each CMHC rate is about four-tenths of the hospital rate.
• CMHC outliers. When a CMHC's cost for a day exceeds 3.40 times the APC payment rate, Medicare pays 50 percent of the excess.
• The hospital composite mental health rate (APC 8010) is set equal to the hospital four-service PHP rate (APC 5864) for 2026.
• FQHCs and RHCs are paid off the hospital three-service amount, which is why the four-service tier doesn't apply to them.
• 2027: CMS proposed the CY 2027 rule in July 2026 (Federal Register) and usually finalizes it in November. Check for the final rule before you budget 2027.

7. How the claim works

• Institutional claim. Hospitals and CMHCs bill program days on the UB-04 (837I), not the CMS-1500, with a condition code identifying the program: 41 for PHP and 92 for IOP. FQHCs and RHCs bill IOP with condition code 92 and revenue code 0905. Our sister site compares the forms in UB-04 vs CMS-1500.
• The services make the day. Each qualifying service is reported with its own code and date, and Medicare assigns the three-service or four-or-more-service per diem from what was furnished that day. A day with fewer than three qualifying services doesn't earn the per diem. CMS's Claims Processing Manual, chapter 4 has the billing rules.
• Commercial plans are different. Most commercial and Medicaid plans pay a program per diem on codes like H0015, S9480 and S0201 instead; see per diem billing for IOP and PHP and IOP and PHP billing codes.

8. Documentation an auditor checks

• The physician certification, signed and dated, with the hour requirement, in the chart before the claim.
• Every PHP recertification on time (18th day, then every 30 days) with its required content; IOP recertification at least every other month.
• An individualized plan of care, established and reviewed by a physician, with goals the daily services work on.
• Each billed service documented on its date with its time, who provided it, and how it relates to the plan.
• Attendance that supports the weekly hours. A client attending well under the certified hours, week after week, raises the question of whether the level of care still fits.
• Progress and discharge planning: why the patient still needs this level, and what moves them down.

The same habits pass a commercial plan's review. Our utilization review guide covers continued-stay reviews, and Comply's chart audit checklist turns them into a monthly sample.

9. Medicare Advantage and dual eligibles

• Medicare Advantage plans cover Medicare benefits through their own networks and set their own credentialing rules. Ask each plan in writing whether it contracts with your program type for IOP or PHP before counting on it. See credentialing with Humana (Medicare Advantage).
• Dual eligibles (Medicare and Texas Medicaid): Medicare is primary. When Medicare won't pay your provider type for the service, ask the Medicaid plan how it handles the claim before you admit, and get it in writing. Verify every Medicare client's coverage at intake with the VOB checklist.

Credentialing the rest of your plans? See how we handle credentialing.

10. Decision guide

Your situation	Medicare answer
Freestanding Texas SUD IOP or PHP (CDTF)	No program-day billing. Enroll your prescriber and licensed therapists to bill their own services; plan revenue from commercial, Medicaid, TRICARE and self-pay.
Freestanding mental health IOP	Same, unless you become a CMHC, which means the four core services and 40 percent non-Medicare clients.
Hospital with an outpatient psychiatric department	PHP and IOP under the hospital's enrollment, paid at the hospital per diem.
FQHC or RHC	IOP at the hospital three-service per diem; not PHP.
Opioid treatment program	IOP for OUD through the G0137 weekly add-on.

Deciding which levels to offer in the first place? See IOP vs. PHP vs. outpatient, and for the program-day rules when part of the week is by video, how to run a virtual IOP.

Questions

Does Medicare cover intensive outpatient programs?

Yes, since January 1, 2024, when furnished by a hospital outpatient department, a community mental health center, an FQHC, a rural health clinic or, for opioid use disorder, an opioid treatment program. A physician must certify that the patient needs at least 9 hours of IOP services a week.

Can a freestanding IOP bill Medicare?

Not for the program day. A freestanding program licensed by the state, such as a Texas chemical dependency treatment facility, isn't a Medicare provider type for IOP or PHP. Its enrolled clinicians, such as physicians, NPs, psychologists, LCSWs, LPCs and LMFTs, can bill their own services.

What is Medicare's 2026 per diem for PHP and IOP?

The CY 2026 final rule sets about $322 for a hospital day with three services and about $422 for four or more, with CMHC rates at about 40% of those (about $129 and $169). PHP and IOP are paid the same within each tier, and rates are wage-adjusted. Check Addendum A of the current rule for exact amounts.

How many hours a week does Medicare require for IOP and PHP?

At least 9 hours a week for IOP and at least 20 hours a week of therapeutic services for PHP, each certified by a physician. PHP is recertified as of the 18th day and then at least every 30 days; IOP no less often than every other month.

Does Medicare pay for substance use IOP?

Yes. Medicare's IOP benefit covers acute mental illness, including substance use disorders, in the provider types above. Opioid treatment programs have their own IOP add-on (G0137) for opioid use disorder.

Can an LCDC bill Medicare?

Generally not on their own. Medicare enrolls LCSWs, psychologists, LPCs and LMFTs (since 2024), NPs and physicians, but not addiction counselors as a separate provider type.

Sources

• CMS, CY 2024 OPPS final rule fact sheet (IOP benefit, provider types, 2024 rates)
• CMS, CY 2026 OPPS final rule fact sheet; CY 2026 OPPS final rule and CY 2027 proposed rule (Federal Register); NABH, 2026 final rule summary
• eCFR: 42 CFR 410.2, 42 CFR 485 subpart J, 42 CFR 424.24, 42 CFR 413.65
• CMS, transmittal on the CMHC 40 percent requirement; CMHC conditions of participation; Noridian, CMHC enrollment
• CMS, Benefit Policy Manual, chapter 6; Claims Processing Manual, chapter 4; OTP billing and payment
• Texas Health and Safety Code ch. 534 (community centers)

Cima Consulting isn't a law or accounting firm. This page summarizes Medicare rules; the regulations, the current OPPS rule and your MAC control.