IOP billing services

IOP billing services for intensive outpatient programs.

HRI bills intensive outpatient programs from verification through appeals: authorization tracked to the date, claims built to each payer's codes and hour rules, and every claim reported each Friday.

Updated September 2026

Request a Billing Review → Where IOP claims break →

Or call 802-424-2455

What IOP billing runs on

Per diem claims, with the unit and the hours set by the payer
S9480 and revenue code 0905 where the payer wants the pair
Medicare: condition code 92, billed by component
Every claim reported every Friday

How IOP claims get paid

IOP is usually paid by the program day, not by the session. The payer sets a per diem for a day that meets its minimum hours, and its manual or your contract says which services sit inside that per diem and which bill on top of it. That is the first rule we read, because the rest of the claim follows from it.

Medicare has covered IOP since January 1, 2024, and pays hospital and community mental health center IOP as a per diem too, for patients whose plan of care calls for at least 9 hours of services a week. It pays only when the program is run by one of the provider types Medicare lists for IOP, and Medicare publishes that list in its own Benefit Policy Manual, chapter 6, section 70.4. A freestanding IOP that is not one of those provider types has no Medicare IOP billing route.

Facility claims go out on the UB-04 and practitioner services on a CMS-1500, and 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. Which form you use depends on your licensure and your payer contracts.

The codes on an IOP claim

There is no single code pair for IOP. The payer, the benefit and the claim form decide, and the published sources do not agree with each other. Here is what each one says. Confirm a plan's current codes and units before you submit.

HCPCS S9480: Intensive outpatient psychiatric services, per diem. It is an HCPCS Level II code, not a CPT code. Commercial payers use it, and so do 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, and says group-therapy codes cannot be accepted for IOP. For Medicare, 0905 is not on the claims manual's list of revenue codes for hospital and community mental health center IOP. Rural health clinics and FQHCs do report it, with condition code 92.
Payers disagree: Indiana's Medicaid manual says procedure codes are not allowed with revenue code 905 and 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: a revenue code and a charge for each covered service, each on its own line with 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. Neither 0905 nor S9480 is on Medicare's list for these claims.
Medicare payment classes: Medicare pays hospital outpatient department and community mental health center IOP as a per diem in four payment classes: 5851 and 5852 for community mental health centers, 5861 and 5862 for hospital outpatient departments. Each pair splits days of up to 3 services from days of 4 or more. Critical access hospitals are paid on cost instead.
Revenue codes 0912 / 0913: Partial hospitalization, less intensive and intensive. These are the PHP codes, not IOP codes.

IOP versus PHP on a claim

Medicare separates the two 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. Partial hospitalization (PHP) needs at least 20 hours a week, and it 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 do not carry 9 and 20 over to a payer's contract.

On the claim, 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, and it returns an IOP claim to the provider when it overlaps a PHP claim, so a step-down from PHP to IOP has to be dated so the two claims never overlap. The PHP side is on the PHP billing services page.

Where IOP claims break

In every case below the care was delivered and the claim still failed.

Authorization and review lapses. A claim goes out before authorization or enrollment is confirmed, or a concurrent review 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, and says that when a patient attends less than 3 hours, the individual services are billed instead. Indiana defines one unit as 3 or more hours and pays one unit per date of service. Bill the per diem for a short day and the claim is wrong on unit logic alone.
Same-day services. The per diem usually covers the program's own services that day, and payers differ on what else can bill beside it. Arizona calls S9480 all-inclusive: other behavioral-health codes cannot be billed 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, though individual counseling for a diagnosis the IOP is not treating can be billed the same day. Indiana allows one IOP code per date of service. Medicare splits it: physician, nurse practitioner, clinical nurse specialist, physician assistant and clinical psychologist services bill separately to the Part B contractor, while 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, so a claim goes to the wrong entity and denies before anyone reads it. Eligibility has to name who processes IOP, not just 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. See medical-necessity denials.
Step-down from PHP. The last PHP date and the first IOP date have to be clean, and each level may need its own authorization. Medicare returns an IOP claim that overlaps a PHP claim.
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. Before any claim goes out we confirm four things for your state: the code, the unit, whether the claim goes to a managed-care plan or to the state on a fee-for-service basis, and the same-day limits. Then we confirm the prior-authorization rule for the level of care.

New Mexico pays S9480 as a daily rate, one unit a day, with a 3-hour minimum. Arizona pays it as an all-inclusive per diem. Indiana pays institutional mental-health IOP a flat rate a day under revenue code 905, with no procedure code on the line. We do not assume that a rule from one state holds in yours.

What we do about it

HRI runs IOP billing under HRI Managed. That means benefit verification, authorization and concurrent review tracked to the date, and claims built to each payer's codes, units and hour documentation before they go out. A denied or stuck claim runs through the same seven-point diagnostic we apply to every claim. Every claim is reported to you every Friday, with its status, its age and the next action.

Opening an IOP

Your license and your setting decide which claim form you bill on and whether Medicare is open to you at all. Settle that before the first admission. For every other payer the work is enrollment: applications, contracts where a network contract applies, and the code pair and unit that payer will accept, confirmed while the application is in and not after the first denial.

One rule is fixed: no claim goes to a payer until that payer confirms enrollment and an effective date. The order of work, what to have ready and the first 90 days are on the new-program billing page.

What it costs

IOP billing runs under the same pricing model as every level of care: a flat fee per claim, set per program day or per encounter where that fits, and a monthly minimum from the first claim. Both are fixed in writing before the first claim, and neither is ever a percentage of what is billed or collected. The fee is owed whether or not a payer pays. Payers pay you directly, and we never receive payer money. Ending the agreement early outside its own exit terms carries an early-exit fee, set in the agreement. There is no setup fee when your operation is ready as it stands.

Some billing companies charge a percentage of what they collect. We do not, so your fee follows the claims we file, not what payers pay. Your exact numbers are set on a written quote after a billing review.

What HRI will not do

We will not promise a payer's authorization decision, a reimbursement rate, or how a plan will read your documentation. Those calls belong to the payer and the reviewer. We will not bill an IOP claim before authorization and enrollment are confirmed. And we have no say in what level of care a patient gets: that decision belongs to your clinical team.

Start with 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, another takes 0905 on the UB-04 and S9480 only on a CMS-1500, and Indiana's Medicaid manual has institutional IOP billed under revenue code 905 with no procedure code at all. 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. We confirm each payer's codes before the first claim goes out.

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 read the unit from the contract before the first claim goes out.

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. 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 92, and it returns an IOP claim that overlaps a PHP claim, so a step-down has to be dated cleanly. 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: other behavioral-health codes cannot be billed during the IOP hours, and a service outside those hours has to be medically necessary and written into the member's service plan. Medicare splits it: physician, nurse practitioner, clinical nurse specialist, physician assistant and clinical psychologist services bill separately to the Part B contractor, while social worker, family therapist and counselor services are bundled 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.

Do you charge a percentage?

No. We charge a flat fee per claim, set per program day or per encounter where that fits, and a monthly minimum from the first claim. Both are fixed in writing before the first claim goes out and are never a percentage of what is billed or collected. The fee is owed whether or not a payer pays, and payers pay you directly.

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

Yes. Aged AR recovery is part of the engagement. We score every open IOP claim for what is still collectible, then correct and re-file the ones worth working while filing and appeal windows are still open. The billing review costs nothing and needs no patient data.

Running IOP claims today?

Start with a billing review.

The review costs nothing, and you do not need to share any patient data to start.

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

Last updated: September 29, 2026