Intensive Outpatient Treatment (also known as IOP for Intensive Outpatient Program) is a primary treatment program recommended in some circumstances by a clinical and medical assessment. IOP may be recommended for those who do not need medically-supervised detox.
The genitive is the case (or function) of an inflected form of a noun or pronoun showing ownership, measurement, association, or source. Adjective: genitival. The suffix -'s on nouns is a marker of genitive case in English. Genitive case can also be indicated by an of phrase after a noun.
The infinitive may be used as a noun, functioning as the subject/pred. nominative or the direct object of the sentence. Infinitive used as a Noun nuber, gender, case. As a noun an infinitive is singular (number), neuter (gender), and either nominative or acc.