ASAM (American Society of Addiction Medicine) outlines five separate levels of addiction treatment on a continuum of care: Early intervention services (0.5) Outpatient treatment (1) IOP/PHP outpatient treatment (2) Residential/inpatient treatment (3) Medically managed intensive inpatient therapy (4) As such, a PHP is classified by ASAM as level 2.5 on the continuum of care. PHPs are more intensive than IOPs but not as intensive as residential rehab.