What is the Limit for Number of Patients for a PHP or IOP Behavioral Health Treatment Program?

The number of patients allowed in either a Partial Hospitalization (PHP) or Intensive Outpatient Program (IOP) for behavioral health varies by state, program, facility and available resources.

No universally fixed limit applies to the number of patients that can participate in an IOP. Some state rules do set group-size limits, so state rules and each payer’s policy govern. Ohio’s rule for behavioral health services, for example, says group counseling and therapy encounters may not exceed a one-to-twelve behavioral health professional to patient ratio.

Four questions come up on this topic:

1. How many patients are allowed to be in PHP/IOP together?

2. Is reimbursement higher for per diem or per session?

3. Can S9480 ever be billed on a CMS 1500 without the revenue code, or must it always be on a UB04?

4. How do you bill using the S9480 code? For example, if a program had 3 patients in treatment who met for 3 hours a day, 3 days a week, what would that look like in terms of insurance billing?

The capacity of a PHP/IOP is how many patients it can hold, and its census is how many are in treatment now. Both depend on factors such as the size of the facility, the staffing levels, the treatment philosophy and the needs of the patients. Some PHPs/IOPs run smaller groups for more individualized attention. Others run larger groups when they have the resources to support them.

The reimbursement rate for IOP (S9480) should not match the rate for individual, family and group therapy (90837/90847/90853). S9480 is per diem (one rate for the whole day of treatment). The per-session codes add up to roughly the same three clinical hours a day. Reimbursement is sometimes equal. Many insurance carriers do not allow multiple therapy services to be billed on the same day, regardless of the modifiers used to specify them. Providers must bill for the services provided.

S9480 is a per diem code that some payers take on the UB-04 and others take on the CMS-1500. A published list of the payers that require S9480 to be billed on the HCFA/CMS 1500 is unlikely to exist.

Carriers change billing requirements. Each carrier can set its own policies on billing procedures, including which form applies to which service.

A carrier’s published provider manual and billing guidelines are where to confirm whether S9480 (the Healthcare Common Procedure Coding System code for intensive outpatient psychiatric services, per diem) is billed on the CMS-1500 form. Providers can ask the carrier directly for its current requirement. We can help with that research.