# How to check for prior authorization requirements in a 271 eligibility response

> Payers require providers to get approval before they’ll cover certain services. This guide shows how to check if prior auth is required for a service.

Published Oct 29, 2025

Updated Nov 9, 2026

Category: Guide

Payers sometimes require providers to get approval before they’ll cover certain services or procedures. That approval is called prior authorization, also known as preauthorization or precertification.

For example, some payers require prior authorization for:

- Elective surgeries, such as joint replacements

- Advanced imaging, such as MRIs or CT scans

- Step therapy, where a patient must try lower-cost treatments before a higher-cost one is approved

Checking for prior authorization before a visit helps prevent denied claims.

This guide shows you how to see if a service requires prior authorization using Stedi’s [JSON Eligibility API](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check).

## Send the eligibility request as usual

You don’t need to include anything special in the [eligibility request](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#body) to get prior authorization details. But the [Service Type Code (STC)](https://www.stedi.com/docs/healthcare/eligibility-stc-procedure-codes) or [procedure code](https://www.stedi.com/docs/healthcare/eligibility-stc-procedure-codes) you use matters. The code tells the payer which services or procedures to return benefits for.

For tips on picking an STC or procedure code, see our [related docs](https://www.stedi.com/docs/healthcare/eligibility-stc-procedure-codes).

## Look for the `priorAuthIndicator`

In a response from our [Real-Time Eligibility Check JSON](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check) endpoint, most benefit details live inside each plan’s [`benefits`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits) object. It groups benefit entries into arrays by type, such as [`statuses`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.statuses) or [`coInsurance`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coInsurance).

Each benefit entry may include a [`service`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coInsurance.service) field. Its [`system`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coInsurance.service.system) and [`value`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coInsurance.service.value) tell you which service (`STC`) or procedure (such as `CPT` or `CDT`) the entry applies to.

If prior authorization is required for a service or procedure, most payers set the benefit entry’s [`priorAuthIndicator`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coInsurance.priorAuthIndicator) field to `REQUIRED`.

| `**priorAuthIndicator**` **value** | **What it means**   |
| ---------------------------------- | ------------------- |
| `REQUIRED`                         | Prior auth required |
| `NOT_REQUIRED`                     | Not required        |
| `U`                                | Unknown             |

If the `priorAuthIndicator` field isn’t included, you can typically assume prior authorization isn’t required.

**Note:** Payers sometimes send incomplete or inaccurate prior authorization information, and Stedi can’t control what they send. An eligibility response isn’t a guarantee of payment, so verify requirements with the payer when the response doesn’t establish them.

**Example: Prior authorization is required for anesthesia**

```jsonc
{
  "plans": [
    {
      "benefits": {
        "coInsurance": [
          {
            "priorAuthIndicator": "REQUIRED",  // Prior authorization is required for anesthesia
            "service": {
              "definition": "Anesthesia",
              "system": "STC",
              "value": "7"
            },
            ...
          }
        ],
        ...
      }
    }
  ],
  ...
}
```

## Check for free-text notes

Some payers include prior authorization details as free-text notes. Look for key phrases like "**prior authorization**" or "**preauthorization**" in each benefit entry’s [`messages`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coPayment.messages) field, such as on a `coPayment` entry.

These notes can clarify or override the `priorAuthIndicator` value.

**Example: Prior authorization is required after 6 mental health visits**

```jsonc
{
  "plans": [
    {
      "benefits": {
        "coPayment": [
          {
            "amount": "20",                     // $20 co-pay
            "messages": [
              "Prior authorization required for mental health visits after 6 sessions."
            ],
            "network": {
              "indicator": "IN_NETWORK"         // Applies to in-network services
            },
            "service": {
              "definition": "Mental Health",
              "system": "STC",
              "value": "MH"
            },
            ...
          }
        ],
        ...
      }
    }
  ],
  ...
}
```

The notes might also show up in a separate benefit entry, such as a `statuses` entry with a [`status`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.statuses.status) of `ACTIVE_COVERAGE`, a [`coverageBasis`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.coverageBasis) entry, or a [`benefitDescription`](https://www.stedi.com/docs/healthcare/api-reference/post-eligibility-check#response.plans.benefits.benefitDescription) entry.

**Example: Prior authorization requirement in a separate entry**

```jsonc
{
  "plans": [
    {
      "benefits": {
        "coverageBasis": [
          {
            "coverageLevel": "INDIVIDUAL",          // Individual coverage
            "messages": [
              "PRECERTIFICATION REQUIRED FOR PET SCANS, CT/CTA SCANS, MRI/MRA SCANS."
            ],
            "network": {
              "indicator": "IN_AND_OUT_OF_NETWORK"  // Applies to in-network and out-of-network services
            }
          }
        ],
        ...
      }
    }
  ],
  ...
}
```

## How to handle the “unknown” value

When the `priorAuthIndicator` field is `U` (unknown), it means the payer can’t determine in real time whether prior authorization is required for the service. The payer may require additional details, like diagnosis or Place of Service, that you can’t provide using an eligibility check. Stedi passes `U` through as-is. For more details, see [Handling `U` (unknown)](https://www.stedi.com/docs/healthcare/eligibility-network-status-authorization-referrals#handling-u-unknown) in our docs.

In these cases, do the following:

- **Check for free-text notes.**  
  Check each benefit entry’s `messages` field for any clarification on prior authorization requirements

- **Contact the payer directly.**  
  Call the payer or use the payer’s provider portal to see if you can get more information. You can use an AI voice agent or screen scraper to do this programmatically. For more details, see [How to deal with gaps in eligibility responses](https://www.stedi.com/blog/how-to-deal-with-gaps-in-eligibility-responses).

- **Use a third-party prior authorization platform.**  
  Stedi’s [Platform Partner directory](https://www.stedi.com/platform-partners) includes trusted vendors that can help you get prior authorization details that aren’t available through an eligibility check.

## Gold carding

Some payers offer “gold carding” programs that let certain providers skip prior authorization requirements. In some cases, gold carding is required by state law.

Unfortunately, you can’t reliably get a provider’s gold card status from a 271 eligibility response. There’s no standard way to indicate it. If you think a provider may qualify, check directly with the payer or provider.

## Next steps

**Get a prior authorization number.**  
The eligibility response only tells you whether the payer requires prior authorization for a service or procedure. It doesn’t actually request it.

You can get a prior auth in one of the following ways:

- Use the payer’s portal or a related payer API. Some payers offer FHIR APIs for prior auth requests and responses.

- Use a third-party prior authorization platform. Check Stedi’s [Platform Partner directory](https://www.stedi.com/platform-partners) for trusted vendors.

In most cases, payers will require the provider to upload or fax supporting documentation.

**Use the prior authorization number in the claim.**  
When the payer approves the request, they’ll give you a prior authorization number. You can include this number in that claim at the claim level. For professional and dental claims, you can also include a prior authorization number at the service-line level.

For example, using Stedi’s [JSON Claims Submission API endpoints](https://www.stedi.com/docs/healthcare/intro-to-claim-submission#api-claim-submission):

```jsonc
{
  "claimInformation": {
    "claimSupplementalInformation": {
      "priorAuthorizationNumber": "PA-12345"  // Claim-level prior auth number
    },
    "serviceLines": [
      ...
      {
        "assignedNumber": "2",
        ...
        "serviceLineReferenceInformation": {
          "priorAuthorization": [
            {
              "priorAuthorizationOrReferralNumber": "PA-67890"  // Service-level prior auth number
            }
          ]
        }
      }
    ]
  }
}
```

## Fast, expert eligibility support

If you ever need help reading an eligibility response, [reach out](mailto:support@stedi.com). Every Stedi customer gets a dedicated Slack or Microsoft Teams channel. Our average response time is under 10 minutes.