ABN Service API

The ABN Service tells you whether an Advance Beneficiary Notice of Noncoverage (ABN) is required for a Medicare patient, based on the account number, test codes, and diagnosis codes. It also returns the estimated cost Medicare is not expected to cover and, optionally, the ABN as a PDF. The full endpoint reference, with request/response schemas, is in the ABN Service API reference.

When you need an ABN

An ABN is required when a Medicare patient may have to pay for a test that Medicare is unlikely to cover, for example because the diagnosis codes don't support medical necessity. The patient must review and sign the ABN before the specimen is collected.

Orders submitted through the Order Submission API are checked for an ABN automatically. Use the ABN Service when you need to know before you submit the order, for example so the patient can sign the ABN before collection.

Check an order

Call POST /checkAbnByTestCodes with the account number, test codes, diagnosis codes, and patient name:

Code
curl -X POST https://abn.services.sandbox.aperture.labcorp.com/checkAbnByTestCodes \
  -H "Authorization: Bearer $ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "accountNumber": "12345678",
    "patientName": "DOE, JANE",
    "testCodes": ["005009", "008847", "004598"],
    "diagCodes": ["R53.83", "R79.89"],
    "includeABNContent": true,
    "includeDetails": true
  }'

• Set includeABNContent to true to receive the ABN PDF, base64-encoded, in abnContents. No PDF is returned without it.
• Set includeDetails to true to receive a per-test breakdown in abnTests.

Read the response

Field	Meaning
isABNRequired	true when an ABN is required for this combination of tests and diagnoses
estCost	Estimated cost not covered by Medicare
abnContents	The ABN PDF, base64-encoded, when includeABNContent was true
abnTests[].medNecCpts	CPT codes whose diagnosis codes don't support medical necessity
abnTests[].freqCpts	CPT codes flagged for Medicare frequency limits
abnTests[].ruoIndicator	true when the test is research-use-only, which always requires an ABN
nonSpecificDiagnosisCodes	Diagnosis codes too non-specific to support medical necessity
invalidDiagnosisCodes	Diagnosis codes the service doesn't recognize
messages	Informational, warning, or error messages, each with code, text, type

Errors

A 200 means the evaluation succeeded. When it doesn't, the service returns 500 with outputType set to "FAILURE" and the reason in messages. Common messages:

Code	Meaning	What to do
ERR0001	Invalid account number	Check the account number.
ERR0002	The account number is not active	In sandbox and certification, use the test account number assigned to you.
ERR0003	Test code was not found	Check the test code.
ERR0004	Test code was found, but it is not orderable	Use a different test code.

Other responses:

• 401: the bearer token is missing or invalid.
• 503: the service is unavailable during periodic database maintenance, which takes roughly 20 minutes. Retry after the number of seconds in the Retry-After header.

If a successful response has no PDF, check that includeABNContent is true.