Risk Adjustment FHIR Models

Note that Zus Risk Adjustment features are currently in public preview and are subject to change.

FHIR Profiles

Risk adjustment data is largely stored as FHIR MeasureReport resources, plus one ExplanationOfBenefit profile for imported risk diagnoses. There are four types:

Resource Type	Profile	Logical Identity	Purpose
Risk Gap (MeasureReport)	`individual-risk-gap`	patient + calendar year + HCC code	A potential diagnosis/coding gap for a single HCC
RAF Score (MeasureReport)	`individual-raf-score`	patient + builder + calendar year	Aggregated risk scores (potential, expected, actual) for a patient
Payer Risk Gap (MeasureReport)	`individual-payer-risk-gap`	patient + reporting period + HCC code + ICD-10 code + payer	Payer reported risk gap data
Risk Diagnoses (ExplanationOfBenefit)	`risk-diagnoses`	patient + source encounter identifier	The diagnoses on a single claim/encounter, with the source's risk-adjustment eligibility verdict

Risk Gap MeasureReport

A Risk Gap represents a single HCC gap for a patient and calendar year.

Core fields

Field	Description
`measure`	`http://zusapi.com/quality/measure/risk/CMSv28`
`subject`	Reference to the patient (e.g., `Patient/{id}`).
`period`	Calendar year window (e.g., `2025-01-01` → `2025-12-31`).
`status`	Always `"complete"`.
`type`	Always `"individual"`.
`date`	When the gap was first calculated.
`meta.profile[]`	Always contains `https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap`

Within group[0] (the Risk Gap group):

Field	Description
`group[0].id`	`risk-gap`
`group[0].measureScore`	The RAF coefficient for the risk gap (when available). Example: `0.123`
`group[0].code.text`	A human readable description of the risk gap. Example: `HCC 280: Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders`
`group[0].code.coding[]`	An array of HCC and ICD-10-CM codes attributable to the risk gap. You can expect: Exactly one HCC v28 code (system: `http://terminology.hl7.org/CodeSystem/cmshcc`, version `28`). At least one ICD-10-CM code (system: `http://hl7.org/fhir/sid/icd-10-cm`). (see ICD-10 codes below)

Risk gap extensions

Risk gaps use extensions to capture key workflow and explanation metadata.

Gap type

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/gap-type`
Type	string
Values	`recapture` \| `suspect` \| `net-new`

Confidence level

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/gap-confidence-level`
Type	integer
Values	`1`–`5` (5 = high confidence, 4 = medium confidence, 1-3 = low confidence)

Status update history

Risk gaps maintain a timeline of status updates.

Level	URL / Field	Description
Container	`https://zusapi.com/fhir/StructureDefinition/risk/status-updates`	Extension container holding the status update history.
Element	`https://zusapi.com/fhir/StructureDefinition/risk/status-update`	A single status update entry.
Field	`https://zusapi.com/fhir/StructureDefinition/status-update/status`	One of `open-gap`, `closed-gap`, `expected-to-close-1st-party`, `expected-to-close-3rd-party`, `accepted-for-review`, `dismissed`.
Field	`https://zusapi.com/fhir/StructureDefinition/status-update/created`	Timestamp when the status was created.
Field	`https://zusapi.com/fhir/StructureDefinition/status-update/created-by`	User/system identifier (e.g., automated calculation vs user action).
Field	`https://zusapi.com/fhir/StructureDefinition/status-update/status-source`	Comma-separated list of contributing sources (e.g., rules-based, AI, payer, user).
Field (optional)	`https://zusapi.com/fhir/StructureDefinition/statusu-update/substatuses`	Additional structured categorization (e.g., `resolved`, `acute-in-nature`).
Field (optional)	`https://zusapi.com/fhir/StructureDefinition/status-update/note`	Free-text note.

Hierarchy relationships (superseding/superseded)

HCCs can supersede other HCCs based on CMS hierarchy rules. Risk gaps can record those relationships using:

Relationship	Extension URL
Superseded by	`https://zusapi.com/fhir/StructureDefinition/risk/hierarchical-status/superseded-by`
Superseding	`https://zusapi.com/fhir/StructureDefinition/risk/hierarchical-status/superseding`

This allows analytics and UI to distinguish "top-level" gaps from gaps that are effectively covered by a higher-priority HCC.

Related clinical objects

Risk gaps can reference additional clinical context useful for human review (e.g., labs, medications, documents).

Level	URL	Description
Container	`https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-objects`	Extension container holding related clinical objects.
Element	`https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-object`	A single related clinical object reference.

Evidence summaries

Each evidence reference on a risk gap — whether in evaluatedResource or under related-clinical-objects — includes a one-line narrative summary describing that piece of
evidence. This summary is stored as an extension directly on the reference.

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/evidence-summary`
Type	string
Location	On each `Reference` in `evaluatedResource` and each `related-clinical-object` entry

These one-liners provide human-readable context for each piece of evidence without requiring the consumer to fetch and interpret the referenced FHIR resource. Note that the format of these summaries may change and should not be relied upon for data ingestion.

Note: For related clinical objects that are Observations or DiagnosticReports with a LOINC code, the summary may use the official LOINC short name for a more concise
label (e.g., "HbA1c" instead of a longer display name).

Gap-level summary

In addition to per-evidence summaries, each risk gap carries a rolled-up narrative summary on the MeasureReport itself. This summary combines all evidence one-liners into a structured, multi-section text organized by evidence type. Note that the format of these summaries may change and should not be relied upon for data ingestion.

The summary is stored as a nested extension:

Level	URL	Type	Description
Container	`https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/summary`	—	Parent extension (no value; children only).
Content	`.../individual-risk-gap/summary/content`	string	The full narrative summary text.
Source	`.../individual-risk-gap/summary/source`	string	How the summary was generated: `"template"` (assembled from structured evidence) or `"ai"` (LLM-generated).

ICD-10 codes

A single risk gap may include one or more ICD-10 codes associated with the HCC. ICD-10 codings can include extensions such as:

URL	Description
`https://zusapi.com/fhir/StructureDefinition/risk/last-encounter-diagnosis-recorded-date`	When that ICD-10 code last appeared as an encounter diagnosis.
`https://zusapi.com/fhir/StructureDefinition/risk/gap-source`	Identifies which source contributed the ICD-10 (e.g., rules-based, AI, payer).

Evidence references (`evaluatedResource`)

Risk gaps use evaluatedResource to link to the inputs that supported the gap.

Example Risk Gap resource

{
  "resourceType": "MeasureReport",
  "id": "7f8d650f-0721-44c5-b10d-fb5611330f0d",
  "meta": {
    "profile": [
      "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap"
    ]
  },
  "status": "complete",
  "type": "individual",
  "measure": "http://zusapi.com/quality/measure/risk/CMSv28",
  "subject": {
    "reference": "Patient/b8238362-db58-4076-8d72-972e5406b574"
  },
  "reporter": {
    "display": "Zus Health"
  },
  "period": {
    "start": "2026-01-01",
    "end": "2026-12-31"
  },
  "date": "2026-02-12",
  "extension": [
    {
      "url": "https://zusapi.com/fhir/identifier/universal-id",
      "valueString": "9133c588-5e7d-49a4-93ac-e2fa3bab695c"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/gap-type",
      "valueString": "suspect"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/gap-confidence-level",
      "valueInteger": 5
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-updates",
      "extension": [
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-update",
          "extension": [
            {
              "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-update/status",
              "valueString": "open-gap"
            },
            {
              "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-update/created",
              "valueDateTime": "2026-02-12T05:45:44.845Z"
            },
            {
              "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-update/created-by",
              "valueString": "zus-risk-gap-calculator"
            },
            {
              "url": "https://zusapi.com/fhir/StructureDefinition/risk/status-update/status-source",
              "valueString": "zus-rules"
            }
          ]
        }
      ]
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-objects",
      "extension": [
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-object",
          "valueReference": {
            "display": "Serum glucose",
            "reference": "Observation/90592907-870e-473b-9f74-afc5285146c2",
            "extension": [
              {
                "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/evidence-summary",
                "valueString": "Serum glucose: 142 mg/dL (2025-09-14)"
              }
            ]
          }
        },
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-object",
          "valueReference": {
            "display": "HbA1c",
            "reference": "Observation/7a759977-fe9c-45d8-8cc3-a1ebaec1153b",
            "extension": [
              {
                "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/evidence-summary",
                "valueString": "HbA1c: 7.2% (2025-09-14)"
              }
            ]
          }
        },
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/related-clinical-object",
          "valueReference": {
            "display": "Lipid Panel",
            "reference": "Observation/90592907-870e-473b-9f74-afc5285146c2",
            "extension": [
              {
                "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/evidence-summary",
                "valueString": "Lipid Panel (2025-09-14)"
              }
            ]
          }
        }
      ]
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/summary",
      "extension": [
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/summary/content",
          "valueString": "Observations:\n• Serum glucose: 142 mg/dL (2025-09-14)\n• HbA1c: 7.2% (2025-09-14)\n• Lipid Panel (2025-09-14)\n\nDiagnoses:\n• E11.9 Type 2 diabetes mellitus without complications — last recorded as encounter diagnosis on 2024-11-19"
        },
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/summary/source",
          "valueString": "template"
        }
      ]
    }
  ],
  "group": [
    {
      "id": "risk-gap",
      "code": {
        "text": "HCC 38: Diabetes with Glycemic, Unspecified, or No Complications",
        "coding": [
          {
            "system": "http://terminology.hl7.org/CodeSystem/cmshcc",
            "version": "28",
            "code": "38",
            "display": "Diabetes with Glycemic, Unspecified, or No Complications"
          },
          {
            "system": "http://hl7.org/fhir/sid/icd-10-cm",
            "code": "E11.9",
            "display": "Type 2 diabetes mellitus without complications",
            "extension": [
              {
                "url": "https://zusapi.com/fhir/StructureDefinition/risk/last-encounter-diagnosis-recorded-date",
                "valueDateTime": "2024-11-19"
              },
              {
                "url": "https://zusapi.com/fhir/StructureDefinition/risk/gap-source",
                "valueString": "zus-rules"
              }
            ]
          }
        ]
      },
      "measureScore": {
        "value": 0.166
      }
    }
  ],
  "evaluatedResource": [
    {
      "type": "Condition",
      "reference": "Condition/1ce7da26-81b6-4d89-b2a7-f5f6dcc88f09",
      "display": "ICD-10 Code: E11.9 - Suspect Encounter Diagnosis",
      "extension": [
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-risk-gap/evidence-summary",
          "valueString": "E11.9 Type 2 diabetes mellitus without complications — last recorded as encounter diagnosis on 2024-11-19"
        }
      ]
    }
  ]
}

RAF Score MeasureReport

A RAF Score aggregates a patient's risk scores for a calendar year.

Core fields

Field	Description
`measure`	`http://zusapi.com/quality/measure/risk/CMSv28`
`subject`	Reference to the patient (e.g., `Patient/{id}`).
`period`	Calendar year window (e.g., `2025-01-01` → `2025-12-31`).
`status`	Always `"complete"`.
`type`	Always `"individual"`.
`date`	When the score was calculated.
`meta.profile[]`	Always contains `https://zusapi.com/fhir/StructureDefinition/risk/individual-raf-score`.

The resource contains three group entries, each representing a different score:

Group ID	Description
`potential-raf-score`	Score if all non-dismissed risk gaps were paid.
`expected-raf-score`	Score using HCCs from gaps with status `expected-to-close-*` or `closed-gap`.
`actual-raf-score`	Score using only HCCs from risk gaps with status `closed-gap` (acknowledged by payer).

RAF Score extensions

RAF Score MeasureReports use extensions to describe the risk adjustment modeling process.

Gap RAF Score Model

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-raf-score/raf-score-model`
Type	string
Values	`CNA` (Community Non-Dual Aged)

Example RAF Score resource

{
  "resourceType": "MeasureReport",
  "id": "[uuid]",

  "meta": {
    "profile": [
      "https://zusapi.com/fhir/StructureDefinition/risk/individual-raf-score"
    ],
    "tag": [
      {
        "system": "https://zusapi.com/lens/owner",
        "code": "builder/[uuid]"
      }
    ]
  },

  "status": "complete",
  "type": "individual",
  "measure": "http://zusapi.com/quality/measure/risk/CMSv28",

  "subject": {
    "reference": "Patient/[uuid]"
  },
  "period": {
    "start": "2026-01-01",
    "end": "2026-12-31"
  },
  "date": "2026-02-12",

  "extension": [
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-raf-score/raf-score-model",
      "valueString": "CNA"
    }
  ],

  "group": [
    {
      "id": "potential-raf-score",
      "measureScore": {
        "value": 1.245
      }
    },
    {
      "id": "expected-raf-score",
      "measureScore": {
        "value": 0.892
      }
    },
    {
      "id": "actual-raf-score",
      "measureScore": {
        "value": 0.654
      }
    }
  ]
}

Payer Risk Gap MeasureReport

A Payer Risk Gap is payer-reported information about a risk gap. We use it as evidence for risk adjustment and for building Risk Gap MeasureReport resources

Core fields

Field	Description
`measure`	`http://zusapi.com/quality/measure/risk/CMSv28`
`subject`	Reference to the patient (e.g., `Patient/{id}`).
`period`	Reporting period window (e.g., `2025-01-01` → `2025-12-31`).
`status`	Always `"complete"`.
`type`	Always `"individual"`.
`meta.profile[]`	Always contains `https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap`.

Within group[0] (the Payer Risk Gap group):

Field	Description
`group[0].id`	`payer-risk-gap`
`group[0].code.coding[]`	An array of HCC and ICD-10-CM codes attributable to the payer risk gap. You can expect: Exactly one HCC v28 code (system: `http://terminology.hl7.org/CodeSystem/cmshcc`, version `V28`). Exactly one ICD-10-CM code (system: `http://hl7.org/fhir/sid/icd-10-cm`).

Payer Risk Gap extensions

Payer Risk Gaps use extensions to describe originally provided payer data.

Gap Source

Item Value

Extension https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/gap-source

Type string

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/gap-source`
Type	string
Values	`payer-risk-gap-csv-file` for Payer Risk Gaps created via CSV Import Files. This is currently the only source for Payer Risk Gap MeasureReports

Values

payer-risk-gap-csv-file for Payer Risk Gaps created via CSV Import Files.

This is currently the only source for Payer Risk Gap MeasureReports

Payer

Customer specific value used for tracking which Payer this Payer Risk Gap is associated to.

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/payer`
Type	string
Values	The value of the `PAYER` column in the original row in the Payer Risk Gap CSV file

Reporting Period

The year most closely associated with this Payer Gap.

Depending on your company policy and relationship with your payer you may need to calculate this value from Calendar Year and/or Payment Year.

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/reporting-period`
Type	string
Values	The value of the `REPORTING_PERIOD` column in the original row in the Payer Risk Gap CSV file

Payer Risk Gap Status

Whether the payer claimed that the risk gap was open or closed.

Item Value

Extension https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/status

Type string

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/status`
Type	string
Values	`open` or `closed` The value of the `GAP_STATUS` column in the original row in the Payer Risk Gap CSV file

Values

open or closed

The value of the GAP_STATUS column in the original row in the Payer Risk Gap CSV file

Payer Risk Gap Recapture Flag

Whether the payer determined this risk gap to have already occurred in the immediately previous reporting period.

Item Value

Extension https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/recapture-flag

Type string

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/recapture-flag`
Type	string
Values	`1` or `0` The value of the `RECAPTURE_FLAG` column in the original row in the Payer Risk Gap CSV file

Values

1 or 0

The value of the RECAPTURE_FLAG column in the original row in the Payer Risk Gap CSV file

Reason

Human readable string describing the evidence behind the payer gap being "open" or "closed" and "recaptured" or "not recaptured".

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/reason`
Type	string
Values	The value of the `REASON` column in the original row in the Payer Risk Gap CSV file

Last Claim Date

The date that the ICD-10 code for this patient last appeared on a claim (or closest approximation).

Item	Value
Extension	`https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/last-claim-date`
Type	string
Values	The value of the `LAST_CLAIM_DATE` column in the original row in the Payer Risk Gap CSV file

Example Payer Risk Gap resource

{
  "extension": [
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/gap-source",
      "valueString": "payer-risk-gap-csv-file"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/recapture-flag",
      "valueString": "1"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/status",
      "valueString": "open"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/last-claim-date",
      "valueString": "2025-08-10"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/reporting-period",
      "valueString": "2026"
    },
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap/payer",
      "valueString": "ACME_INSURANCE_MA"
    },
    {
      "url": "https://zusapi.com/fhir/identifier/universal-id",
      "valueString": "[uuid]"
    }
  ],
  "group": [
    {
      "code": {
        "coding": [
          {
            "code": "J44.9",
            "system": "http://hl7.org/fhir/sid/icd-10-cm"
          },
          {
            "code": "280",
            "system": "http://terminology.hl7.org/CodeSystem/cmshcc",
            "version": "V28"
          }
        ]
      },
      "id": "payer-risk-gap"
    }
  ],
  "id": "[uuid]",
  "measure": "http://zusapi.com/quality/measure/risk/CMSv28",
  "meta": {
    "extension": [
      {
        "url": "https://zusapi.com/stream",
        "valueString": "third-party"
      },
      {
        "url": "https://zusapi.com/created-at",
        "valueInstant": "2026-02-25T15:52:30.59+00:00"
      }
    ],
    "lastUpdated": "2026-02-25T15:52:30.571+00:00",
    "profile": [
      "https://zusapi.com/fhir/StructureDefinition/risk/individual-payer-risk-gap"
    ],
    "tag": [
      {
        "code": "builder/[uuid]",
        "system": "https://zusapi.com/accesscontrol/owner"
      }
    ],
    "versionId": "1"
  },
  "period": {
    "end": "2026-12-31",
    "start": "2026-01-01"
  },
  "resourceType": "MeasureReport",
  "status": "complete",
  "subject": {
    "reference": "Patient/[uuid]",
    "type": "Patient"
  },
  "type": "individual"
}

Risk Diagnoses ExplanationOfBenefit

A Risk Diagnoses resource is a single claim or encounter whose risk-adjustment eligibility has already been determined by the source (for example, a CMS MAO-004 report or a payer EDPS file). Each resource carries all of the encounter's ICD-10-CM diagnosis codes and one encounter-level eligibility verdict. We use it as evidence for risk adjustment: risk-eligible encounters feed recapture and net-new risk gap calculation, while non-eligible encounters feed suspecting.

Unlike the other risk models, Risk Diagnoses are stored as FHIR ExplanationOfBenefit resources rather than MeasureReport resources, because they represent the payer's processed view of a claim/encounter. Today the only source of Risk Diagnoses resources is the Risk Diagnoses CSV Import.

Core fields

Field	Description
`meta.profile[]`	Always contains `https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses`.
`identifier[]`	Contains exactly one identifier with system `https://zusapi.com/fhir/identifier/risk/source-encounter-id`. The value is the `ENCOUNTER_IDENTIFIER` from the CSV row (for MAO-004 sources, the encounter ICN). This identifier is the identity of the resource: resubmitting the same encounter updates the existing resource in place rather than creating a new one.
`patient`	Reference to the patient (e.g., `Patient/{id}`).
`billablePeriod`	The service dates of the encounter (`start` from `SERVICE_START_DATE`, `end` from `SERVICE_END_DATE`).
`type`	The claim type, from `SERVICE_TYPE`: `professional` (`P`) or `institutional` (`I` or `O`), in the system `http://terminology.hl7.org/CodeSystem/claim-type`.
`insurer.display`	The `PAYER` value from the CSV row.
`provider.display`	The `PROVIDER` value from the CSV row.
`insurance[0].coverage.display`	The `PAYER` value from the CSV row. There is no contained `Coverage` resource.
`created`	The date the row was imported. Note this is not the source's timestamp; see the `source-updated-at` extension below.
`status`	Always `"active"`.
`use`	Always `"claim"`.
`outcome`	Always `"complete"`.

Within diagnosis[]:

Field	Description
`diagnosis[n].sequence`	1-based position of the code in the CSV row's `ICD_10_CM_CODES` list.
`diagnosis[n].diagnosisCodeableConcept.coding[]`	Exactly one ICD-10-CM code (system: `http://hl7.org/fhir/sid/icd-10-cm`), in dotted form (e.g., `E11.319`). Duplicate codes from the CSV row are collapsed into a single entry.

The resource does not carry financial adjudication data: item and item.adjudication are not populated.

Risk Diagnoses extensions

Risk Diagnoses use a single complex extension to carry the encounter-level risk-adjustment facts from the source.

Risk adjustment eligibility

Level	URL	Type	Description
Container	`https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses/risk-adjustment-eligibility`	-	Parent extension (no value; children only). Present exactly once on every resource.
Status	`.../risk-adjustment-eligibility/status`	code	`eligible` or `not-eligible`. The source's risk-adjustment eligibility verdict for the encounter, from the `RISK_ELIGIBLE` column in the original row in the Risk Diagnoses CSV file (`true` maps to `eligible`, `false` maps to `not-eligible`). The verdict covers every diagnosis on the resource.
Source updated at	`.../risk-adjustment-eligibility/source-updated-at`	instant	When the producing source last changed this encounter's determination. The value of the `SOURCE_UPDATED_AT` column in the original row in the Risk Diagnoses CSV file. This is the version guard for restatements: a resubmission is applied only if its value is newer than the stored one.

Example Risk Diagnoses resource

Produced from a CSV row for a risk-eligible professional encounter with two diagnoses:

{
  "resourceType": "ExplanationOfBenefit",
  "id": "[uuid]",
  "meta": {
    "profile": [
      "https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses"
    ],
    "tag": [
      {
        "code": "builder/[uuid]",
        "system": "https://zusapi.com/accesscontrol/owner"
      }
    ],
    "lastUpdated": "2026-02-01T15:52:30.571+00:00",
    "versionId": "1"
  },
  "extension": [
    {
      "url": "https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses/risk-adjustment-eligibility",
      "extension": [
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses/risk-adjustment-eligibility/status",
          "valueCode": "eligible"
        },
        {
          "url": "https://zusapi.com/fhir/StructureDefinition/risk/risk-diagnoses/risk-adjustment-eligibility/source-updated-at",
          "valueInstant": "2026-02-01T00:00:00Z"
        }
      ]
    }
  ],
  "identifier": [
    {
      "system": "https://zusapi.com/fhir/identifier/risk/source-encounter-id",
      "value": "9999999999999"
    }
  ],
  "status": "active",
  "type": {
    "coding": [
      {
        "system": "http://terminology.hl7.org/CodeSystem/claim-type",
        "code": "professional"
      }
    ]
  },
  "use": "claim",
  "patient": {
    "reference": "Patient/[uuid]",
    "type": "Patient"
  },
  "billablePeriod": {
    "start": "2026-01-02",
    "end": "2026-01-02"
  },
  "created": "2026-02-01",
  "insurer": {
    "display": "MEDICARE"
  },
  "provider": {
    "display": "Acme Medical Group"
  },
  "outcome": "complete",
  "insurance": [
    {
      "focal": true,
      "coverage": {
        "display": "MEDICARE"
      }
    }
  ],
  "diagnosis": [
    {
      "sequence": 1,
      "diagnosisCodeableConcept": {
        "coding": [
          {
            "system": "http://hl7.org/fhir/sid/icd-10-cm",
            "code": "E11.319"
          }
        ]
      }
    },
    {
      "sequence": 2,
      "diagnosisCodeableConcept": {
        "coding": [
          {
            "system": "http://hl7.org/fhir/sid/icd-10-cm",
            "code": "I50.9"
          }
        ]
      }
    }
  ]
}

FHIR Profiles

Risk Gap MeasureReport

Core fields

Risk gap extensions

Gap type

Confidence level

Status update history

Hierarchy relationships (superseding/superseded)

Related clinical objects

Evidence summaries

Gap-level summary

ICD-10 codes

Evidence references (evaluatedResource)

Example Risk Gap resource

RAF Score MeasureReport

Core fields

RAF Score extensions

Gap RAF Score Model

Example RAF Score resource

Payer Risk Gap MeasureReport

Core fields

Payer Risk Gap extensions

Gap Source

Payer

Reporting Period

Payer Risk Gap Status

Payer Risk Gap Recapture Flag

Reason

Last Claim Date

Example Payer Risk Gap resource

Risk Diagnoses ExplanationOfBenefit

Core fields

Risk Diagnoses extensions

Risk adjustment eligibility

Example Risk Diagnoses resource

Evidence references (`evaluatedResource`)