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Medical bill audit API

Send the line items from a bill or EOB, get back the billing errors with an explanation and an estimated recoverable amount.

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Who it’s for

Patient-billing platforms
Check a bill for errors before it is presented for payment.
TPAs and self-insured employers
Screen claims on behalf of the population you cover.
HSA/FSA administrators
Flag a charge before the account holder spends against it.
Care navigation and advocacy
Give advocates the arithmetic behind each finding.

We don’t sell this to health plans as the primary buyer, since a health plan benefits when a claim is denied. See pricing.

What it detects

Duplicate charges
The same service billed twice on one bill or across providers.
Cost-share errors
Deductible / coinsurance / copay computed wrong against the plan.
Denials & coordination of benefits
PR-22 and other reason codes that shift a denial onto the patient.
Balance billing (NSA)
Out-of-network amounts billed above the allowed/protected rate.
Unbundling
Codes billed separately that should be a single bundled charge (NCCI).
Implausible charges
Amounts wildly out of line with what the service plausibly costs.

Example

Request

curl -X POST https://paxer.app/api/v1/audit \
  -H "Authorization: Bearer pax_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "lineItems": [
      { "description": "Echocardiogram, complete", "cptHcpcsCode": "93306",
        "chargeAmount": 980, "allowedAmount": 710, "planPaid": 0,
        "patientResponsibility": 710, "adjustmentCodes": ["PR-22"] }
    ]
  }'

Response

{
  "findings": [
    {
      "type": "NON_COVERED_BILLED_TO_PATIENT",
      "severity": "HIGH",
      "title": "Denial billed to you: coordination-of-benefits denial (reason code PR-22), echocardiogram",
      "explanation": "Your plan allowed $710 but paid $0, and the full $710 was passed to you under a PR-22 coordination-of-benefits denial. Denials like this are frequently reversed.",
      "recommendedNextStep": "Submit the primary plan's EOB to this insurer, or call to correct your coordination-of-benefits record so the claim reprocesses. Consider waiting to pay until it has been reprocessed.",
      "estimatedRecovery": 710,
      "confidence": 0.75,
      "detector": "RULE",
      "lineItemIndex": 0
    }
  ],
  "summary": {
    "findingCount": 1,
    "estimatedRecoverable": 710
  },
  "usage": {
    "plan": "free",
    "used": 1,
    "quota": 100
  }
}

Status codes

Audit API status codes
CodeMeaning
200Findings returned. summary.estimatedRecoverable is capped so it never exceeds total patient responsibility.
400Invalid request body, e.g. missing or malformed lineItems. The response "error" field explains.
401Missing or invalid API key. Send it as Authorization: Bearer pax_live_... (or the x-api-key header).
402Monthly quota exceeded. This calendar month’s audit allotment is used up. Upgrade for a higher quota.
429Rate limited (120 requests/min per key). Retry after the window resets.

Quota is per calendar month and hard-capped, so over the limit returns 402, with no surprise overage charges. Usage resets on the 1st. Keys are created and revoked in Settings → Developers.

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