(1) "Case management" services means services furnished to assist Medicaid and mental health services plan eligible individuals who reside in a community setting, or are transitioning to a community setting, in gaining access to needed medical, social, educational, and other services.

(2) "Episode of decompensation" means increased symptoms of psychosis, self-injury, suicidal or homicidal intent, or psychiatric hospitalization.

(3) "Medically necessary service" means a service or item reimbursable under the Montana Medicaid program, as provided in ARM 37.82.102:

(a) that is reasonably calculated to prevent, diagnose, correct, cure, alleviate, or prevent the worsening of conditions in a patient which:

(i) endanger life;

(ii) cause suffering or pain;

(iii) result in illness or infirmity;

(iv) threaten to cause or aggravate a handicap; or

(v) cause physical deformity or malfunction.

(b) A service or item is not medically necessary if there is another service or item for the individual that is equally safe and effective and substantially less costly including, when appropriate, no treatment at all.

(c) Experimental services or services that are generally regarded by the medical profession as unacceptable treatment are not medically necessary for purposes of the Montana Medicaid program.

(d) Experimental services are procedures and items, including prescribed drugs, considered experimental or investigational by the U.S. Department of Health and Human Services, including the Medicare program, or the department's designated review organization, or procedures and items approved by the U.S. Department of Health and Human Services for use only in controlled studies to determine the effectiveness of such services.

(4) "Severe disabling mental illness" is defined in ARM 37.86.3503.