Levels of Care

PHP vs IOP: what's the difference?

Both are outpatient, but they're not the same level of care. Here's how partial hospitalization and intensive outpatient compare.

By Level Up Compliance · Updated May 2026 · ~5 min read

The difference between PHP and IOP is intensity. A partial hospitalization program (PHP) is the more intensive outpatient level — typically around 20 or more hours of clinical programming per week, often five to six days a week. An intensive outpatient program (IOP) is less intensive — commonly around 9 to 15 hours per week across about three days. Both let clients live at home; PHP sits just below residential care, and IOP is a step down from PHP.

Side by side

 PHP (Partial Hospitalization)IOP (Intensive Outpatient)
IntensityHigher — just below residentialLower — a step down from PHP
Typical hours~20+ hours/week, ~5–6 days~9–15 hours/week, ~3 days
Lives at home?YesYes
Best forClients needing structured daily support without 24-hour careClients stable enough for part-time structure, often stepping down

How clients move between them

Treatment is usually a continuum. A client might begin in residential or detox, step down to PHP for structured daily support, then step down again to IOP as they stabilize, and finally to standard outpatient. Offering more than one level of care lets a program keep clients through that journey rather than discharging them — but each level carries its own licensing, staffing, and clinical requirements.

Building one or both? See our guides on how to start an IOP program and what a PHP is — each level needs its own licensing and accreditation to bill insurance.

Frequently asked questions

What is the difference between PHP and IOP?

The difference is intensity. A partial hospitalization program (PHP) is more intensive — around 20 or more hours of programming per week, often five to six days. An intensive outpatient program (IOP) is less intensive — about 9 to 15 hours per week across roughly three days. Both let clients live at home.

Is PHP more intensive than IOP?

Yes. PHP is the more intensive outpatient level of care, sitting just below residential treatment, while IOP is a step down from PHP with fewer weekly hours.

Can a client step down from PHP to IOP?

Yes. Treatment is typically a continuum — clients often move from residential or detox to PHP, then step down to IOP as they stabilize, and finally to standard outpatient care.

Do PHP and IOP require different licensing?

Yes. Each level of care carries its own licensing, staffing, and clinical requirements, and accreditation is typically required to bill insurance for either.

Related guides

What Is a PHP?

Partial hospitalization, the day-treatment level of care.

How to Start an IOP Program

Launch an intensive outpatient program.

How to Open a Rehab Center

The full sequence from level of care to opening.

Want this handled for you?

Level Up Compliance guides behavioral health founders through every step — licensing, accreditation, contracting, and operations.