Physical therapists should review the authorization approval letter from TriWest that is sent in response to the authorization request for physical therapy services. The letter provides the date range for which services have been approved. If services are not provided within that date range, a new referral from the primary care manager (PCM), Military Treatment Facility (MTF), or specialist is required to avoid higher out-of-pocket costs for the beneficiary under the point-of-service (POS) option and potential delays in care.
Also, if the authorization approval letter indicates that services are “NOT APPROVED” because “…TriWest has not received a referral from the Primary Care Manager (PCM) or from a Military Treatment Facility (MTF) provider for this specialty within the previous 180 days or the time period noted in the initial referral,” then the services will pay under POS unless the beneficiary obtains a referral from their PCM or MTF. If not considered medically necessary, physical therapy services may be denied.
Please note that physical therapy exceeding 20 visits per episode of care requires a prior authorization for beneficiaries over age 21. Also, any combination of physical therapy and occupational therapy greater than 40 visits per episode for beneficiaries over age 21 also requires prior authorization.
Refer to the Referrals/Authorizations section of TriWest.com/Provider for more information about the referral and authorization process and available resources.

Source: Tricare eNews; August 8, 2012