D84.8 ICD-10-CM Code: Other specified immunodeficiencies

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for D84.8 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025

Notes without a marker are published on D84.8 itself; “inherited from” names the category or block whose note applies here.

This page already reflects the FY2027 tabular note taking effect October 1, 2026.

Coder workflow for D84.8

MedCoder structured workflow — derived from this code’s own official record

Before you code D84.8

1. D84.8 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewD84.81, D84.82, D84.89

   See the relationships section · Guide: How to choose an ICD-10-CM code →

2. “Other” (NEC) means the condition is specified in the record but no dedicated code captures it. Confirm the documented form is not one a sibling code names before settling on D84.8; if the record states no specifics at all, the unspecified sibling applies instead. “Other” codes are for documented conditions the classification gives no specific code; “unspecified” codes are for records lacking the detail (Guidelines I.A.9.a, I.A.9.b).

   ReviewD84.0, D84.1

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with D84.8. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the documentation support one of the more specific codes beneath D84.8?
   Yes → Select that code and continue the checks below on its own page.
   No → D84.8 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewD84.81, D84.82, D84.89

2. Does the documentation support a condition named in D84.8’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewM35.9, D71

Consider D84.8. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes1 — check before selecting D84.8(2 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with D84.8: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareM35.9, D71

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of D84.8(1 note)

  Coding workflow: The conditions named in this note are not included in D84.8. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareB20

  See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse D84.8 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of D84.8 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• M35.9— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of autoimmune disease (systemic) NOS moves the case to M35.9; the two are not reported together unless documented as unrelated.

  Full comparison: D84.8 vs M35.9 →

• D71— Excludes1 conflict (Excludes1 — generally not reported together)

  Not coded here — the tabular list excludes this pair for the same encounter.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of functional disorders of polymorphonuclear neutrophils moves the case to D71; the two are not reported together unless documented as unrelated.

  Full comparison: D84.8 vs D71 →

• D84.9— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Immunodeficiency, unspecified” takes D84.9; specificity in the record moves it back here.

  Full comparison: D84.8 vs D84.9 →

• B20— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of human immunodeficiency virus [HIV] disease adds B20; it is not part of this code and both may be reported when both are documented.

  Full comparison: D84.8 vs B20 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Verify Before Coding

• Not billable as written — a more specific code is required: D84.81, D84.821, D84.822, D84.89.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name D84.8 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: D72 — Other disorders of white blood cells (via D84.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Clinical classification (AHRQ CCSR):BLD008 — Immunity disorders (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Immunity disorders).

D82.4 — Hyperimmunoglobulin E [IgE] syndrome, D82.8 — Immunodeficiency associated with other specified major defects, D82.9 — Immunodeficiency associated with major defect, unspecified, D83.0 — Common variable immunodeficiency with predominant abnormalities of B-cell numbers and function, D83.1 — Common variable immunodeficiency with predominant immunoregulatory T-cell disorders, D83.2 — Common variable immunodeficiency with autoantibodies to B- or T-cells, D83.8 — Other common variable immunodeficiencies, D83.9 — Common variable immunodeficiency, unspecified, D84.0 — Lymphocyte function antigen-1 [LFA-1] defect, D84.1 — Defects in the complement system, D84.81 — Immunodeficiency due to conditions classified elsewhere, D84.821 — Immunodeficiency due to drugs, D84.822 — Immunodeficiency due to external causes, D84.89 — Other immunodeficiencies, D84.9 — Immunodeficiency, unspecified, D86.0 — Sarcoidosis of lung, D86.1 — Sarcoidosis of lymph nodes, D86.2 — Sarcoidosis of lung with sarcoidosis of lymph nodes, D86.3 — Sarcoidosis of skin, D86.81 — Sarcoid meningitis, +64 more

Contextual Map

Every relationship of D84.8 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run D84.8 with this related code in Claim Check

Hierarchy

• D50-D89 — Chapter 3: Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) (D50-D89)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D80-D89 — Certain disorders involving the immune mechanism[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• D72 — Other disorders of white blood cells[Excludes1](via D84.-): “immunity disorders (D80-D89)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• BLD008 — Immunity disorders[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

Nearest codes (9)

• D84 — Other immunodeficiencies[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.0 — Lymphocyte function antigen-1 [LFA-1] defect[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.1 — Defects in the complement system[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.81 — Immunodeficiency due to conditions classified elsewhere[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.82 — Immunodeficiency due to drugs and external causes[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.821 — Immunodeficiency due to drugs[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.822 — Immunodeficiency due to external causes[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• D84.89 — Other immunodeficiencies[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 1 more

Change history (4)

• FY2027 — Excludes2 note will be added[Change history]— CMS release files (code change ledger) · icd10cm-fy2027
• and 3 more

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to D84.8 in its code family, with their registry titles.

• D84 — Other immunodeficiencies
• D84.0 — Lymphocyte function antigen-1 [LFA-1] defect
• D84.1 — Defects in the complement system
• D84.81 — Immunodeficiency due to conditions classified elsewhere
• D84.82 — Immunodeficiency due to drugs and external causes
• D84.821 — Immunodeficiency due to drugs
• D84.822 — Immunodeficiency due to external causes
• D84.89 — Other immunodeficiencies
• D84.9 — Immunodeficiency, unspecified

View all codes in the D84 family