Introducing MBI lookups without an SSN

You can now look up a patient’s Medicare Beneficiary Identifier (MBI) without a Social Security Number (SSN).

Every Medicare beneficiary is assigned a unique ID called the MBI. It’s printed on their Medicare card. You need it for all eligibility checks and claims for Medicare Part A and Part B – also called Original Medicare.

When a patient doesn’t know their MBI, you can use Stedi's Eligibility APIs or the Stedi portal to find it before running an eligibility check.

Previously, an MBI lookup required the patient’s SSN. But front-desk teams often don’t have a patient’s SSN on file. Now, you can perform the same lookup without one.

Two types of MBI lookups

With this update, you can now perform an MBI lookup in two ways. Each uses a different payer ID:

Type	Payer ID	Required patient data
MBI lookup with SSN	`MBILU`	First name, last name, date of birth, SSN
MBI lookup without SSN	`MBILUNOSSN`	First name, last name, date of birth, U.S. state

Note: When running an MBI lookup without SSN using our raw X12 or SOAP eligibility endpoints, you must include a city, in addition to a U.S. state, in Loop 2100C N4. You can use a dummy city value, such as DUMMY, if needed. If you omit the city value, you'll receive an X12 validation error.

Whenever possible, use MBI lookups with an SSN. They return results more consistently. Use lookups without an SSN as a fallback for when you don’t have the SSN on file.

You don't need to include more patient demographic information than what's required, such as additional address data. It doesn’t improve MBI lookup success rates.

Transaction enrollment

Before running an MBI lookup without an SSN, enroll the provider for eligibility checks with the MBILUNOSSN payer ID using the Transaction Enrollment API or the Stedi portal.

First, create a provider record. For example, using the Create Provider endpoint:

curl --request POST \
  --url "https://enrollments.us.stedi.com/2024-09-01/providers" \
  --header "Authorization: <api_key>" \
  --header "Content-Type: application/json" \
  --data '{
    "taxIdType": "EIN",       
    "taxId": "123456789",            // Billing provider's EIN
    "name": "Acme Health Services",  // Billing provider's name
    "npi": "1999999984",             // Billing provider's NPI
    ...
  }'

The response includes a provider ID:

{
  "id": "db6665c5-7b97-4af9-8c68-a00a336c2998", // Provider ID
  "name": "Acme Health Services",
  ...
}

Use the returned provider ID to create an enrollment request for eligibility checks with the MBILUNOSSN payer ID. For example, using the Create Enrollment endpoint:

curl --request POST \
  --url "https://enrollments.us.stedi.com/2024-09-01/enrollments" \
  --header "Authorization: <api_key>" \
  --header "Content-Type: application/json" \
  --data '{
    "transactions": {
      "eligibilityCheck": {
        "enroll": true  // Enroll for eligibility checks
      }
    },
    ...
    "payer": {
      "idOrAlias": "MBILUNOSSN"  // Payer ID for MBI lookups without an SSN
    },
    "provider": {
      "id": "db6665c5-7b97-4af9-8c68-a00a336c2998"  // Provider ID
    },
    "source": "API",
    "status": "STEDI_ACTION_REQUIRED"
  }'

Enrollments for the MBILUNOSSN payer typically take 1-3 business days to complete.

You’ll get an email once the enrollment is live. You can also check enrollment status using the List Enrollments or Retrieve Enrollment API endpoints.

Run an MBI lookup without an SSN

After the enrollment is live, send an eligibility check to MBILUNOSSN. Include:

The provider’s NPI
The patient’s first name
The patient’s last name
The patient’s date of birth
The patient’s U.S. state
The patient's city (if using the raw X12 or SOAP eligibility endpoints)

Don’t include other patient information, like extra address data. It doesn’t improve lookup success rates.

For example, using Stedi’s JSON Eligibility API:

curl --request POST \
  --url https://healthcare.us.stedi.com/2024-04-01/change/medicalnetwork/eligibility/v3 \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '{
  "tradingPartnerServiceId": "MBILUNOSSN",
  "externalPatientId": "UAA111222333",
  "encounter": {
    "serviceTypeCodes": [
      "30"
    ]
  },
  "provider": {
    "organizationName": "ACME Health Services",
    "npi": "1999999984"
  },
  "subscriber": {
    "dateOfBirth": "19000101",
    "firstName": "Jane",
    "lastName": "Doe",
    "address": {
      "state": "NY"
    }
  }
}'

If there's a match, Stedi submits an eligibility check to the Centers for Medicare and Medicaid Services (CMS) – the government payer for Medicare – and returns the complete eligibility response.

The response includes the MBI as the subscriber’s member ID. The response shape is the same as that used for MBI lookups with an SSN. For example:

{
  "subscriber": {
    "memberId": "1AA2CC3DD45",  // Patient's MBI
    "firstName": "JANE",
    "lastName": "DOE",
    ...
    "address": {
      "state": "NY",
      ...
    }
  },
  ...
}

For more details, see our MBI lookup docs.

Pricing

For rates, see our pricing page.

Get a free consult

If you’re building a Medicare eligibility workflow, get in touch. We can help you integrate MBI lookups at scale.

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