What is ICD-10 code E31.9?

E31.9 is the ICD-10-CM diagnosis code for Polyglandular dysfunction, unspecified. A condition affecting multiple hormone-producing glands, but the specific type or nature of the dysfunction is not documented. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E31.9 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E31.9 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E31.9 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E31.9 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does E31.9 map to under V28?

E31.9 maps to CMS-HCC V28 51 (Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does E31.9 pay in RAF?

E31.9 carries a community, non-dual, aged (CNA) RAF weight of 0.510 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for E31.9?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For E31.9, V28 maps to Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders at RAF 0.510 while V24 mapped to Other Significant Endocrine and Metabolic Disorders at RAF 0.194. Both models can still appear in legacy data and in payer-specific lookback periods.

What documentation supports E31.9?

This is a non-specific code; query the provider for more detailed documentation to assign a more specific E31 code Review lab results and clinical presentation to determine if a more specific diagnosis code applies Because E31.9 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM E31.9: Polyglandular

E31.9 maps to CMS-HCC V28 51 (RAF 0.510). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupE31.9Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Disorders of other endocrine glands (E20-E35)

E31.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Polyglandular dysfunction, unspecified

A condition affecting multiple hormone-producing glands, but the specific type or nature of the dysfunction is not documented.

Buddy Insight

CMS-HCC V28

Mapped

HCC 51

Addison's and Cushing's Disea...

RAF 0.510

CMS-HCC V24

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.194

ACA/HHS

Mapped

HCC 30

HHS-HCC 30

Varies by metal level

ESRD/PACE

Mapped

HCC 23

Other Significant Endocrine a...

RAF 0.036

RXHCC

Mapped

HCC 43

Other Significant Endocrine a...

RAF 0.063

Code Book Path

Official

E31Polyglandular dysfunction

E31.9Polyglandular dysfunction, unspecified

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for E31.9 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E31.9 in this effective period.

Related Child Codes

Official

E31.0Autoimmune polyglandular failure

E31.1Polyglandular hyperfunction

E31.2Multiple endocrine neoplasia [MEN] syndromes

E31.8Other polyglandular dysfunction

Includes

Official

ICD-10-CM does not list Includes notes for E31.9 in this effective period.

Excludes 1

Official

ataxia telangiectasia [Louis-Bar] (G11.3)
dystrophia myotonica [Steinert] (G71.11)
pseudohypoparathyroidism (E20.1)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E31.9 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E31.9 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E31.9 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must identify which endocrine glands are affected (adrenal, thyroid, parathyroid, gonadal, pancreatic) and the specific dysfunctions present.

Lab values including hormone levels (cortisol, thyroid-stimulating hormone, parathyroid hormone, insulin, sex hormones) should be recorded.

The provider should specify if this represents an autoimmune polyglandular syndrome (Type I, II, or III) to enable assignment of a more specific code.

MEAT Support

HCC Buddy guidance

Documentation must identify which endocrine glands are affected (adrenal, thyroid, parathyroid, gonadal, pancreatic) and the specific dysfunctions present.

Lab values including hormone levels (cortisol, thyroid-stimulating hormone, parathyroid hormone, insulin, sex hormones) should be recorded.

The provider should specify if this represents an autoimmune polyglandular syndrome (Type I, II, or III) to enable assignment of a more specific code.

Audit Caution

HCC Buddy guidance

Avoid using this unspecified code when documentation supports a specific polyglandular syndrome.

Do not assign this code for single-gland endocrine disorders even if multiple hormones from that gland are affected.

Ensure the provider has explicitly documented polyglandular involvement rather than inferring it from multiple separate endocrine diagnoses in the problem list.

Common Mistakes

HCC Buddy guidance

E31.0 (Autoimmune polyglandular failure) should be used when autoimmune etiology is confirmed.

E31.1 (Polyglandular hyperfunction) captures overactivity rather than dysfunction.

Individual gland disorder codes (E03.x for hypothyroidism, E27.x for adrenal insufficiency) may be more appropriate when only one or two glands are affected rather than a true polyglandular pattern.

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is E31.9 an HCC code?

Yes. E31.9 (Polyglandular dysfunction, unspecified) maps to Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24), with a community non-dual aged RAF of 0.510. It is billable for payment year 2026.

Coder answer: E31.9 is billable and maps to V28 HCC 51, Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: E31.9
Description: Polyglandular dysfunction, unspecified
HCC (V28): HCC 51 — Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders
RAF: 0.510
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 51, Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders

0.510

V24HCC 23, Other Significant Endocrine and Metabolic Disorders

0.194

ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders

0.036

RxHCCHCC 43, Other Significant Endocrine and Metabolic Disorders

0.063

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work E31.9 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E31.9

For E31.9 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E31.9 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E31.9 is the ICD-10-CM diagnosis code for polyglandular dysfunction, unspecified. A condition affecting multiple hormone-producing glands, but the specific type or nature of the dysfunction is not documented. E31.9 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering disorders of other endocrine glands (e20-e35).

Under the CMS-HCC V28 risk adjustment model, E31.9 maps to Addison's and Cushing's Diseases, Acromegaly, and Other Specified Endocrine Disorders (HCC 51) with a community, non-dual, aged base RAF weight of 0.510. Under the older CMS-HCC V24 model, E31.9 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.194. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

This is a non-specific code; query the provider for more detailed documentation to assign a more specific E31 code. Because E31.9 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E31.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is a non-specific code; query the provider for more detailed documentation to assign a more specific E31 code
•Review lab results and clinical presentation to determine if a more specific diagnosis code applies

Clinical Significance

Polyglandular dysfunction involves failure or dysfunction of multiple endocrine glands simultaneously, leading to complex hormonal imbalances that can affect metabolism, growth, reproduction, and stress response. This unspecified code signals that the provider has identified multi-gland involvement but has not specified the exact syndrome or pattern, which is critical for accurate risk adjustment and treatment planning.

Documentation Requirements

✓Documentation must identify which endocrine glands are affected (adrenal, thyroid, parathyroid, gonadal, pancreatic) and the specific dysfunctions present.
✓Lab values including hormone levels (cortisol, thyroid-stimulating hormone, parathyroid hormone, insulin, sex hormones) should be recorded.
✓The provider should specify if this represents an autoimmune polyglandular syndrome (Type I, II, or III) to enable assignment of a more specific code.

Commonly Confused Codes

•E31.0 (Autoimmune polyglandular failure) should be used when autoimmune etiology is confirmed.
•E31.1 (Polyglandular hyperfunction) captures overactivity rather than dysfunction.
•Individual gland disorder codes (E03.x for hypothyroidism, E27.x for adrenal insufficiency) may be more appropriate when only one or two glands are affected rather than a true polyglandular pattern.