What is ICD-10 code D82.8?

D82.8 is the ICD-10-CM diagnosis code for Immunodeficiency associated with other specified major defects. An immunodeficiency condition linked to other significant genetic or developmental abnormalities not covered by more specific codes. D82.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D82.8 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. D82.8 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. D82.8 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.

What is the V28 vs V24 difference for D82.8?

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. D82.8 was a payment HCC under V24 (Disorders of Immunity) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting D82.8?

Use this code only when the major defect is specified but doesn't fit other D82 categories Document the associated major defect clearly in the medical record for specificity Because D82.8 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.

D82.8: Immunodeficiency associated with other

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupD82.8Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) / Certain disorders involving the immune mechanism (D80-D89)

D82.8

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

Immunodeficiency associated with other specified major defects

An immunodeficiency condition linked to other significant genetic or developmental abnormalities not covered by more specific codes.

Buddy Insight

Immunodeficiency associated with other specified major defects encompasses rare syndromic immunodeficiency disorders with defined genetic or developmental abnormalities that do not fit the specific categories of Wiskott-Aldrich, DiGeorge, short-limbed immunodeficiency, or Epstein-Barr virus susceptibility syndromes.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 47

Disorders of Immunity

RAF 0.472

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 47

Disorders of Immunity

RAF 0.0

RXHCC

Mapped

HCC 99

Immunodeficiencies

RAF 0.0

Code Trumping

Basket needed

Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

D82Immunodeficiency associated with other major defects

D82.8Immunodeficiency associated with other specified major defects

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D82.8 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D82.8 in this effective period.

Related Child Codes

Official

D82.0Wiskott-Aldrich syndrome

D82.1Di George's syndrome

D82.2Immunodeficiency with short-limbed stature

D82.3Immunodeficiency following hereditary defective response to Epstein-Barr virus

D82.4Hyperimmunoglobulin E [IgE] syndrome

Includes

Official

ICD-10-CM does not list Includes notes for D82.8 in this effective period.

Excludes 1

Official

ataxia telangiectasia [Louis-Bar] (G11.3)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D82.8 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for D82.8 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for D82.8 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must specify the particular major defect associated with the immunodeficiency, include genetic testing confirming the underlying condition, immunological assessment showing the specific immune deficits, and description of the associated non-immune features.

Document the relationship between the major defect and the immunodeficiency to support code assignment.

MEAT Support

HCC Buddy guidance

Document the relationship between the major defect and the immunodeficiency to support code assignment.

Audit Caution

HCC Buddy guidance

Ensure the documented major defect is truly associated with immunodeficiency and not a coincidental finding.

For ataxia-telangiectasia, code the neurological manifestation separately (G11.3).

This code should not be used for immunodeficiency due to medications or external causes, which have their own specific codes (D84.821, D84.822).

Verify the defect does not fit D82.0-D82.4 before using this code.

Common Mistakes

HCC Buddy guidance

D82.0 through D82.4 (specific syndromic immunodeficiencies that should be used when applicable), D82.9 (immunodeficiency associated with major defect, unspecified), D81.89 (other combined immunodeficiencies without associated major defects), G11.3 (ataxia-telangiectasia which has its own neurological code but may also require D82.8 for the immune component).

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is D82.8 an HCC code?

Yes. D82.8 maps to Disorders of Immunity under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 47, Disorders of Immunity

0.472

ESRDHCC 47, Disorders of Immunity

0.000

RxHCCHCC 99, Immunodeficiencies

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for D82.8

For D82.8to 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 D82.8 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

Get the V28 RAF + MEAT cheat sheet

One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

D82.8 is the ICD-10-CM diagnosis code for immunodeficiency associated with other specified major defects. An immunodeficiency condition linked to other significant genetic or developmental abnormalities not covered by more specific codes. D82.8 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering certain disorders involving the immune mechanism (d80-d89).

Under the older CMS-HCC V24 model, D82.8 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.472. 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.

Use this code only when the major defect is specified but doesn't fit other D82 categories. Because D82.8 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 D82.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the major defect is specified but doesn't fit other D82 categories
•Document the associated major defect clearly in the medical record for specificity

Clinical Significance

Documentation Requirements

✓Documentation must specify the particular major defect associated with the immunodeficiency, include genetic testing confirming the underlying condition, immunological assessment showing the specific immune deficits, and description of the associated non-immune features.
✓Document the relationship between the major defect and the immunodeficiency to support code assignment.

Commonly Confused Codes

•D82.0 through D82.4 (specific syndromic immunodeficiencies that should be used when applicable), D82.9 (immunodeficiency associated with major defect, unspecified), D81.89 (other combined immunodeficiencies without associated major defects), G11.3 (ataxia-telangiectasia which has its own neurological code but may also require D82.8 for the immune component).