IOP billing services

IOP billing services for intensive outpatient programs.

Health Revenue Intelligence (HRI) bills intensive outpatient programs (IOP) from verification through appeals. We track authorization to the date and build claims to each payer's codes and hour rules.

Updated October 2026

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What IOP billing runs on

Per diem claims, with the unit and hours set by the payer
S9480 and revenue code 0905 where the payer wants the pair
Medicare: condition code 92, billed by component
Each IOP claim reported every Friday, with its status, age and next action

How IOP claims get paid

IOP is usually paid by the program day, not by the session. The payer sets a per diem, one payment for each day that meets its minimum hours. The payer's manual or your contract says which services sit inside that per diem and which bill on top of it. We read that rule first.

Medicare has covered IOP since January 1, 2024. It pays hospital and community mental health center IOP as a per diem too. Medicare pays only when one of the provider types it lists for IOP runs the program. The list is in Medicare's Benefit Policy Manual, chapter 6, section 70.4. A freestanding IOP outside those provider types has no Medicare IOP billing route.

Facility claims go out on the UB-04 and practitioner services on the CMS-1500. The IOP day itself can go on either, depending on the payer. New Mexico's Medicaid supplement lists S9480 on the CMS-1500. Indiana's manual takes S9480 on professional claims and revenue code 905 on institutional ones. Your licensure and your payer contracts decide which form you use.

The codes on an IOP claim

There is no single code pair for IOP. The payer, the benefit and the claim form decide it, and the published sources below do not agree with each other. We confirm each plan's current codes and units before we bill that plan.

HCPCS S9480: Intensive outpatient psychiatric services, per diem. It is an HCPCS Level II code, used by commercial payers and by some state Medicaid programs, among them Arizona, Indiana and New Mexico. CMS describes S codes as private-payer codes that Medicare does not pay.
Revenue code 0905: Intensive outpatient services, psychiatric, on the UB-04 facility claim. One commercial payer's billing guide lists mental-health IOP as 905 with S9480. Another's facility handbook asks for 0905 on a UB-04 and S9480 only on a CMS-1500. The same handbook says group-therapy codes cannot be accepted for IOP. Medicare's claims manual does not list 0905 among its revenue codes for hospital and community mental health center IOP. Rural health clinics and federally qualified health centers (FQHCs) do report 0905.
Payers disagree: Indiana's Medicaid manual does not allow procedure codes with revenue code 905. Indiana Medicaid pays those lines a flat rate a day. One commercial payer's 2023 provider alert asks hospital outpatient departments for 0905 with a valid CPT or HCPCS code. A claim template built for one of them fails the other.
Condition code 92: Hospitals and community mental health centers must put condition code 92 on every Medicare IOP claim. Rural health clinics and FQHCs use it too.
Medicare bill types: 013X for a hospital, 076X for a community mental health center and 085X for a critical access hospital. Rural health clinics use 71X and FQHCs use 77X.
Medicare billing method: Hospitals and community mental health centers bill by component. Each covered service gets its own line, with a revenue code, a charge and its date of service. Group therapy, for example, goes under 0915 with G0410, G0411 or 90853. Critical access hospitals do not have to report the HCPCS codes or the line dates.
Medicare payment classes: Medicare groups hospital outpatient department and community mental health center IOP into four payment classes. Community mental health centers use 5851 and 5852, and hospital outpatient departments use 5861 and 5862. Each pair splits days of up to 3 services from days of 4 or more. Critical access hospitals are paid on cost instead.

IOP versus PHP on a claim

Medicare separates IOP from partial hospitalization (PHP) by hours and by need. Under Medicare, IOP needs at least 9 hours of services a week in the plan of care. A physician certifies that need and recertifies at least every 60 days. PHP needs at least 20 hours a week and is for patients who would otherwise need inpatient psychiatric care. IOP patients do not. Those are Medicare's numbers. Commercial and Medicaid payers set their own hours, so the 9 and the 20 do not carry over to a payer's contract.

PHP goes under revenue code 0912 or 0913 where the payer uses them, and IOP does not. Medicare marks PHP claims with condition code 41 and IOP claims with condition code 92. The PHP side is on the PHP billing services page.

Where IOP claims break

Seven denial patterns recur on IOP claims.

Authorization and review lapses. A claim goes out before authorization or enrollment is confirmed, or the payer's concurrent review of further treatment days lapses mid-program and every day after it goes unpaid. Indiana's Medicaid manual, for one, requires prior authorization for intensive outpatient treatment. Our note on how to do an authorization covers the steps.
Unit miscounts. A per diem is payable only for a day that meets the payer's minimum hours. Arizona's Medicaid guide treats S9480 as an all-inclusive per diem for programs of 3 or more hours a day on 2 or more days a week. Arizona's guide says individual services are billed instead when a patient attends less than 3 hours. Indiana defines one unit as 3 or more hours and pays one unit per date of service. A per diem billed for a short day is wrong on unit logic alone.
Same-day services. The per diem usually covers the program's own services that day. Payers differ on what else can bill beside it. Arizona Medicaid bars other behavioral-health codes during the IOP hours, and a service outside those hours has to be medically necessary and written into the member's service plan. New Mexico's daily rate includes individual and group therapy. Under New Mexico Medicaid, individual counseling for a diagnosis the IOP is not treating can be rendered the same day. Indiana allows one IOP code per date of service. Medicare splits the day's services by provider type. Physician, nurse practitioner, clinical nurse specialist, physician assistant and clinical psychologist services bill separately to the Part B contractor. Social worker, family therapist and counselor services sit inside the facility claim. Our note on psych visits beside a per diem goes further.
The wrong payer entity. Many plans hand behavioral health to a separate manager. A claim sent to the wrong entity denies before anyone reads it. Eligibility has to name who processes IOP as well as who issued the card.
Missing notes and attendance. The record has to show the hours for each day billed. Medicare also wants an individualized written plan of care and a physician certification behind the claim. A day without that record is a day the payer can refuse. When the record falls short, our guide to medical-necessity denials sets out the response.
Step-down from PHP. The last PHP date and the first IOP date have to be clean, and Medicare returns an IOP claim that overlaps a PHP claim. Each level may need its own authorization.
Telehealth days. Payers differ on whether they cover an IOP day delivered by video and on how they want it reported. We wrote up what to verify for S9480 telehealth.

Medicaid IOP

Medicaid IOP rules are set state by state, so before any claim goes out we confirm your state's code, unit and same-day limits. The same check covers the prior-authorization rule for the level of care. It also tells us whether the claim goes to a managed-care plan or to the state on a fee-for-service basis.

New Mexico pays S9480 as a daily rate, one unit a day, with a 3-hour minimum.

What we do about it

We bill IOP under HRI Managed, our billing service, which covers benefit verification and tracks each concurrent review date. No IOP claim goes out before its authorization is confirmed. A denied or stuck claim goes through our seven-point diagnostic.

Opening an IOP

Your license and your setting decide which claim form you bill on and whether Medicare is open to you. We check both before the first admission. For every other payer the work is enrollment: the applications and any network contract. We confirm the code pair and unit that payer will accept while the application is pending, before any denial.

No claim goes to a payer until that payer confirms enrollment and an effective date. Our new-program billing page lays out the order of work and what to have ready.

What it costs

Your exact numbers are set on a written quote after a billing review.

IOP billing, answered

What providers ask about IOP claims.

What codes are used for IOP billing?

There is no single pair, because the payer decides. For mental-health IOP, commercial payers and some state Medicaid programs use S9480, a per diem HCPCS code. One commercial payer's guide puts S9480 with revenue code 0905 on the UB-04, while another takes 0905 on the UB-04 and S9480 only on a CMS-1500. Medicare hospital and community mental health center IOP is billed by component with condition code 92, and neither S9480 nor 0905 is on Medicare's code list for those claims.

Is IOP paid per day, per session or per hour?

Usually per program day. S9480 is a per diem code, Medicare pays hospital and community mental health center IOP as a per diem, and the Medicaid manuals we checked in Arizona, Indiana and New Mexico all pay it as a per diem. All three set a 3-hour minimum for the day, so a day counts only if it meets the payer's minimum hours. A payer's contract can define the unit differently, so we take the unit from the contract itself.

How does IOP billing differ from PHP?

They differ in hours, codes and level of care. Medicare's IOP minimum is 9 hours a week and its PHP minimum is 20, and PHP is for patients who would otherwise need inpatient care. On the claim, PHP takes revenue code 0912 or 0913 where the payer uses them, and IOP does not. Medicare tells the two apart by condition code, 41 for PHP and 92 for IOP. Commercial and Medicaid payers set their own hours.

Does Medicare cover IOP?

Yes, since January 1, 2024, but only from the provider types Medicare lists for IOP, in its Benefit Policy Manual, chapter 6, section 70.4. It needs a physician's certification of at least 9 hours of services a week under an individualized plan, recertified at least every 60 days. A freestanding IOP that is not one of those provider types has no Medicare billing route.

Can we bill individual therapy or a psychiatry visit on the same day as the per diem?

It depends on the payer. Arizona's Medicaid guide calls S9480 all-inclusive and bars other behavioral-health codes during the IOP hours. Medicare lets physician, nurse practitioner, clinical nurse specialist, physician assistant and clinical psychologist services bill separately, and bundles social worker, family therapist and counselor services into the facility claim. We read the payer's rule first and code the day to it. Our note on psych visits with a per diem IOP has more.

Can you take over an IOP with denials already piling up?

Yes. Recovering aged AR is part of the engagement. We score each open IOP claim for whether it can still be paid, then correct and re-file the ones worth working while their filing and appeal windows are open.

Running IOP claims today?

Start with a billing review.

It costs you nothing, and you can start without sharing any patient data.

Request a Billing Review → Call 802-424-2455 →

A Business Associate Agreement is in place before any PHI is exchanged. For addiction-treatment programs, we also sign a 42 CFR Part 2 qualified service organization agreement before handling any records. Security & Compliance

Last updated: October 25, 2026