UB04 Condition Codes Code A0: TRICARE External Partnership Program

Overview

Condition Code A0 is part of the standard Condition Code set maintained by the Centers for Medicare & Medicaid Services (CMS) and published by Medicare Administrative Contractors such as Noridian. ^[1]

The MassHealth UB-04 Billing Guide does not list Code A0, as it is a federal (TRICARE) code rather than a state‑specific code. ^[2]

When to Use

The code is placed in one of the Condition Code fields (18–28) on the UB-04. It is typically used in conjunction with other codes that identify the patient’s insurance type (e.g., in Field 50 – Payer ID) and may be required by the TRICARE contractor for proper routing and adjudication. ^[1]

Providers should verify with their TRICARE contractor or the patient’s health plan whether Code A0 is mandatory for specific partnership arrangements. Incorrect or missing condition codes can lead to claim delays or denials.

Step-by-Step Claim Example

Scenario: A military retiree receives outpatient physical therapy at a hospital‑based clinic. The patient’s coverage is through the TRICARE External Partnership Program (a contracted network plan). The provider submits a UB-04 claim.

1. Patient Information (Fields 1–13): Enter the patient’s name, address, date of birth, and sex.
2. Condition Codes (Fields 18–28): In the first available Condition Code field, enter A0 to indicate TRICARE External Partnership Program.
3. Payer Information (Fields 50–66): In Field 50, enter the TRICARE payer ID (e.g., “TRICARE” or the specific contractor ID). In Field 51, enter the health plan ID if different.
4. Service Lines (Fields 42–49): List the physical therapy services with appropriate revenue codes (e.g., 0420 for physical therapy) and HCPCS codes.
5. Diagnosis Codes (Fields 67–75): Enter the primary and secondary ICD‑10 codes.
6. Submit: Send the claim to the TRICARE contractor or intermediary as instructed.

The presence of Code A0 alerts the payer that the claim should be processed under the external partnership rules, which may affect benefit calculations, copayments, and network reimbursement rates.

Common Mistakes & Audit Red Flags

• Using Code A0 for standard TRICARE coverage: Code A0 is specific to the External Partnership Program. For standard TRICARE Prime, Standard, or Extra, use other appropriate codes (e.g., Code 48 for psychiatric residential treatment center claims). ^[1]
• Omitting the code entirely: Failure to include A0 when the patient is in an external partnership may result in the claim being processed under standard TRICARE rules, leading to incorrect payment or denial.
• Placing the code in the wrong field: Condition Codes must be entered in Fields 18–28. Entering A0 in a different field (e.g., Occurrence Code field) will cause the code to be ignored.
• Conflicting codes: Do not use A0 together with other TRICARE‑specific condition codes that describe a different program (e.g., Code 46 – Nonavailability statement on file) unless the situation truly warrants both. ^[1]
• Not verifying patient eligibility: Always confirm that the patient is currently enrolled in the External Partnership Program before applying Code A0. Using the code for ineligible patients can trigger audits and recoupments.

Related Codes/Fields

The following table lists other TRICARE‑related condition codes from the Noridian set, along with the relevant UB-04 fields.

Code	Meaning	UB-04 Field(s)
A0	TRICARE External Partnership Program	Fields 18–28
46	Nonavailability statement on file	Fields 18–28
48	Psychiatric RTC for children and adolescents (TRICARE)	Fields 18–28
26	VA eligible patient chooses to receive services in a Medicare Certified Facility	Fields 18–28
01	Military service related; coordinate with the Department of Veterans Affairs (VA)	Fields 18–28

Source: ^[1]

Additional fields affected by Condition Codes:

• Field 50 – Payer ID: Must match the TRICARE contractor for the partnership program.
• Field 51 – Health Plan ID: May be required for specific partnership plans.
• Field 39 – Value Codes: May be used to report additional amounts (e.g., patient liability) that interact with condition code logic.

Always refer to the latest TRICARE billing manual or your Medicare Administrative Contractor for complete guidance on condition code usage.

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References

[1] Noridian Condition Codes — https://med.noridianmedicare.com/web/jea/topics/claim-submission/condition-codes

[2] MassHealth UB-04 Guide — https://www.mass.gov/doc/ub-04-billing-guide-0/download