---
title: "Prior Authorization"
description: "Local, stateful API emulators for healthcare and life science development. FHIR, SMART on FHIR, EHRs, payers, and life science APIs, without PHI. Synthetic data only."
canonical_url: "https://www.emuhealth.dev/docs/priorauth"
---
# Prior Authorization

An emulator of a synthetic payer's [Da Vinci](https://www.hl7.org/about/davinci/) prior authorization services, for EHR and provider apps that build to the CMS Interoperability and Prior Authorization rule. It runs on `http://localhost:4129` with:

- a [CRD](https://hl7.org/fhir/us/davinci-crd/) (Coverage Requirements Discovery) CDS service at `/cds-services`;
- [DTR](https://hl7.org/fhir/us/davinci-dtr/) (Documentation Templates and Rules) questionnaire packages at `/fhir`;
- [PAS](https://hl7.org/fhir/us/davinci-pas/) (Prior Authorization Support) `Claim/$submit` and `Claim/$inquire` at `/fhir`.

```bash
npx emuhealth --service priorauth
curl http://localhost:4129/cds-services
```

It is not affiliated with any payer. The rules and decisions are synthetic.

## Coverage rules

Decisions come from rules keyed by HCPCS Level II codes, which are public:

| HCPCS | Item | Prior auth | Documentation | PAS decision |
| --- | --- | --- | --- | --- |
| `E0601` | CPAP device | Required | Clinical, questionnaire `home-cpap` | Pended, then approved on inquiry |
| `E1390` | Oxygen concentrator | Required | Clinical, questionnaire `home-oxygen` | Approved |
| `K0001` | Standard wheelchair | Not required | None | Approved |
| `E0260` | Semi-electric hospital bed | Required | Administrative, questionnaire `hospital-bed` | Denied |

Other codes are treated as needing prior authorization, and a PAS request for them stays pended.

## Coverage Requirements Discovery

`GET /cds-services` lists `coverage-requirements-order-sign` and `coverage-requirements-order-select`, each asking for `patient` and `coverage` prefetch. `POST /cds-services/{id}` with `context.draftOrders` (DeviceRequest or ServiceRequest with an HCPCS code) and a coverage prefetch returns:

- a `systemActions` entry per order that adds the CRD `ext-coverage-information` extension: `coverage`, `covered`, `pa-needed`, `doc-needed`, `questionnaire`, `date`, and `coverage-assertion-id`;
- a card per order with the rule's note, and a link to the DTR questionnaire when documentation is needed.

Without a coverage prefetch, the service answers with one warning card.

## Documentation Templates and Rules

`POST /fhir/Questionnaire/$questionnaire-package` with a Parameters body holding `coverage` and `order` resources (or `questionnaire` canonicals) returns a `PackageBundle` per questionnaire. The questionnaires prefill the patient's name and birth date with SDC `initialExpression` in FHIRPath. DTR's CQL libraries are not emulated.

## Prior Authorization Support

`POST /fhir/Claim/$submit` takes a PAS request Bundle whose Claim has `use: preauthorization` and an identifier. The response Bundle starts with a ClaimResponse:

- `outcome`: `complete` when every item is approved, `queued` when one is pended, `error` when all are denied, and `partial` otherwise;
- `preAuthRef` and `preAuthPeriod` when approved;
- per item, an `urn:emuhealth:extension:priorauth-review-decision` extension (`approved`, `pended`, or `denied`).

PAS conveys item decisions with X12 review action codes, which are licensed, so the emulator uses that stand-in extension instead.

`POST /fhir/Claim/$inquire` with a Bundle holding a Claim with the same identifier returns the current decision. A pended request is decided at the inquiry. Claims and ClaimResponses are stored, so `GET /fhir/ClaimResponse` lists them.

PAS Subscriptions for pended decisions are not emulated; inquire instead.