TRICARE prior authorization by region, plan and service

TRICARE uses two terms. A referral is when the patient’s primary care manager sends them to another provider for care the manager doesn’t provide, and a pre-authorization is when the regional contractor approves care before the appointment, according to TRICARE. Which one a request needs depends on the patient’s plan, and which contractor reviews it depends on the patient’s region.

Humana Military reviews requests in the East Region, TriWest Healthcare Alliance in the West Region and International SOS in the Overseas Region. TriWest took over the West Region from Health Net Federal Services on January 1, 2025, according to ASHA (October 2024). TRICARE serves about 9.5 million beneficiaries, according to the Congressional Research Service (November 2025).

At a glance

• Humana Military has not taken outpatient requests by fax since January 1, 2025.
• Six states moved from the East Region to the West Region on January 1, 2025.
• TriWest stopped taking its Alternative Referral and Authorization form on April 30, 2026.
• TriWest does not accept retroactive authorizations, so requests go in before the visit.
• A TRICARE pharmacy appeal goes to Express Scripts first.

Who reviews TRICARE requests in each region

The patient’s region decides which contractor reviews the request. Contractors and phone numbers are from TRICARE’s regions page (September 2026), and the submission routes from each contractor’s provider guidance:

Humana Military stopped taking outpatient requests by fax when its East Region contract began on January 1, 2025, according to its provider FAQ (November 2024). On the same date Arkansas, Illinois, Louisiana, Oklahoma, Texas and Wisconsin moved from the East Region to the West Region, a change affecting about 1.1 million beneficiaries, according to the Military Health System (August 2024). Some ZIP codes in Arkansas and Wisconsin stayed in the East Region, and some in Indiana and Missouri changed region, according to Military Times (December 2024), so check the patient’s region before you send a request.

Referral or pre-authorization: what each TRICARE plan needs

TRICARE’s referrals and pre-authorizations page (October 2026) sets out what each plan needs:

A Prime patient who sees a specialist without a referral is using the point-of-service option and pays more out of pocket.

Which services need pre-authorization

For the plans outside Prime, TRICARE lists seven kinds of care that need pre-authorization: adjunctive dental services, ABA, home health, hospice, transplants (solid organ and stem cell), all Extended Care Health Option (ECHO) services and some Provisional Coverage services.

The contractors’ own lists are longer. TriWest’s prior authorization list (revised July 24, 2025) also includes durable medical equipment, home infusion, inpatient rehabilitation, non-emergency inpatient stays, pain management, spine surgery, skilled nursing facility care, intensive outpatient and partial hospitalization programs, and Spravato under the medical benefit. Humana Military’s September 2024 flyer also lists bariatric surgery and hip surgery for femoroacetabular impingement, and says its list changes periodically. TriWest was not accepting retroactive authorizations as of its April 2026 provider FAQ, so the request needs to go in before the visit.

TRICARE prior authorization forms

TRICARE prior authorization forms for drugs come from the TRICARE Formulary Search Tool, where the provider downloads the form for the drug, and TRICARE’s pharmacy forms page (October 2026) also offers a general Brand Name Over Generic Prior Authorization Request. Completed drug forms go to Express Scripts by fax at 866-684-4477 or by email to TpharmPA@express-scripts.com.

Medical requests have no single TRICARE form and go through Humana Military’s provider self-service in the East Region and Availity in the West Region. TriWest stopped accepting its Alternative Referral and Authorization form on April 30, 2026, and still takes requests by fax at 866-852-1893, according to the California Medical Association (May 2026). US Family Health Plan publishes its own forms.

Check which Humana Military and TriWest requests Silna can submit

ABA under the Autism Care Demonstration

TRICARE covers ABA through the Autism Care Demonstration (ACD), and a child needs a referral to the ACD and a pre-authorization for all ABA services. According to TRICARE’s ACD page (September 2026):

• An authorization covers six months of ABA services
• The provider requests reauthorization every six months
• A new referral is needed every two years
• Four baseline outcome measures are completed before ABA starts

The ACD is authorized through December 31, 2028. A National Academies report in September 2025 recommended making ABA a basic TRICARE benefit, and a June 26, 2026 letter from Senators Gillibrand and Schmitt said no action had been taken on it.

Behavior One Autism Solutions, an ABA practice, saves 40 minutes per prior authorization with Silna.

How long TRICARE takes to decide and how long approval lasts

In the West Region, TriWest reports that most authorizations are decided within two business days, in its July 2026 update.

TriWest’s provider FAQ (April 2026) says a request that needs medical necessity review can take up to five days, and that urgent requests are only for care needed within three days. In the East Region, Humana Military tells beneficiaries to allow up to five business days for an authorization to appear in self-service, according to its beneficiary FAQ (November 2024).

How long each approval lasts:

Drug prior authorization through Express Scripts

Express Scripts runs the TRICARE pharmacy benefit. TRICARE’s pharmacy prior authorization page (September 2026) lists four reasons a drug may need prior authorization: the DoD Pharmacy and Therapeutics Committee names it, it is a brand-name drug with a generic substitute, it has age limits, or the prescribed amount is above the normal limit. Approval takes about 10 days after Express Scripts receives the request, according to a TRICARE questions-and-answers article (May 2025).

Some drugs are pre-authorized under the medical benefit instead. TriWest’s list includes Spravato (esketamine) nasal spray. A TRICARE pharmacy appeal goes to Express Scripts first, with an optional second level, unlike the plans in the Express Scripts guide, where the plan hears the appeal. For Express Scripts’ rules on other plans, see the guide to Express Scripts prior authorization, and for drugs in general, the guide to prior authorization for medication.

When TRICARE denies a pre-authorization

A medical necessity appeal must be postmarked within 90 days of the date on the decision, according to TRICARE’s appeals page (October 2026). The appeal goes to the contractor first. After its decision, a reconsideration by the TRICARE Quality Monitoring Contractor can be requested within another 90 days, and a disputed amount of $300 or more can then go to an independent hearing.

In the West Region, TRICARE’s appeals page for the region says an expedited appeal is filed within three calendar days of receiving the denial, and that a network participating provider needs a signed Authorization of Representative form to file an appeal. TriWest takes appeals by fax at 866-852-1919. These steps differ from the commercial, Medicare and Medicaid ones in the guide to appealing a prior authorization denial.

Where Silna fits in TRICARE referrals and authorizations

For each request, Silna checks the patient’s plan and region and whether the service needs a referral, a pre-authorization or both, then submits it through the contractor’s channel with the clinical documents and follows up until a decision comes back. For ABA, it tracks each six-month authorization and the referral’s end date so the next request goes in on time. For how Availity requests work, see the Availity prior authorization guide.

Silna’s insurance monitoring flags a patient’s plan change. Before Silna, a client’s switch of medical plans went undetected at Behavior One for three months and cost the practice over $10,000 in unbillable services.

Tell Silna about your TRICARE requests

Key terms

Regional contractor

The company that reviews referrals and pre-authorizations for a TRICARE region: Humana Military in the East, TriWest Healthcare Alliance in the West and International SOS overseas.

Primary care manager (PCM)

The provider assigned to a TRICARE Prime enrollee, who sends the patient to other providers by referral.

Referral

The primary care manager or provider sending a patient to another provider for care they don’t provide.

Pre-authorization

The regional contractor’s approval of care before the appointment.

Autism Care Demonstration (ACD)

The TRICARE program that covers ABA, with its own referral and six-month authorizations.

Frequently Asked Questions

Does TRICARE Select need a referral?

Only for ABA, which needs a referral to the Autism Care Demonstration. Home health and hospice are among the services that still need pre-authorization.

Who handles TRICARE prior authorization in the West?

TriWest Healthcare Alliance, since January 1, 2025. Requests go through Availity, and TriWest still accepts them by fax at 866-852-1893.

Where do TRICARE drug prior authorization forms come from?

From the TRICARE Formulary Search Tool, which lists the form for each drug that has one. If the tool has no form for the drug, TRICARE says to contact Express Scripts.

How long is a TriWest PCM referral valid?

Between 180 and 365 days, according to TriWest’s April 2026 provider FAQ. Once a referral or authorization expires, a new request is needed.

How often does ABA need reauthorization under TRICARE?

Every six months. The ACD referral itself is renewed every two years.

This article is general educational information and does not give medical, legal or insurance advice. TRICARE’s contractors change their lists and processes during the year, so check the contractor’s current notice before you send a request.

About the author

Jeffrey Morelli

Jeffrey Morelli is the Co-Founder and CEO of Silna Health, the first Care Readiness Platform built to remove the administrative barriers that delay care. Silna automates benefit checks, eligibility, and prior authorizations across 1,000+ payors, and is backed by $27M from Accel and Bain Capital Ventures. Before Silna, Jeff spent a decade in San Francisco building and scaling products for highly regulated industries, including leading go-to-market at Truework (Series C, acquired by Checkr).

Last updated: October 20, 2026.