D81.9 — Combined immunodeficiency, unspecified
D81.9 is a billable, specific ICD-10-CM code for combined immunodeficiency, unspecified. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Severe combined immunodeficiency disorder [SCID] NOS
Risk adjustment
D81.9 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 114 Common Variable and Combined Immunodeficiencies2.262 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.
Medicare coverage
D81.9 is named in 25 Medicare coverage policies — 25 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52507External Infusion Pumps - Policy Article
- A52509Intravenous Immune Globulin - Policy Article
- A54660Billing and Coding: Coverage of Intravenous Immune Globulin for Treatment of Primary Immune Deficiency Diseases in the Home – Medicare Benefit Policy Manual, Chapter 15, 50.6
- A55717Billing and Coding: Lab: Flow Cytometry
How D81.9 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to D81.9.
- Agammaglobulinemia›lymphopenic
- Immunodeficiency›combined
- Immunodeficiency›severe combined(SCID)
- Syndrome›combined immunity deficiency
- Syndrome›immunity deficiency, combined
- Agammaglobulinemia›with›lymphopenia
- Deficiency, deficient›immunity›combined
- Immunodeficiency›combined›severe(SCID)
- Syndrome›immunodeficiency›combined
Related codes at this level
Codes that share D81. If D81.9 is not quite right, the correct code is usually one of these.
- D81.0Severe combined immunodeficiency [SCID] with reticular dysgenesis
- D81.1Severe combined immunodeficiency [SCID] with low T- and B-cell numbers
- D81.2Severe combined immunodeficiency [SCID] with low or normal B-cell numbers
- D81.3Adenosine deaminase [ADA] deficiency
- D81.4Nezelof's syndrome
- D81.5Purine nucleoside phosphorylase [PNP] deficiency
- D81.6Major histocompatibility complex class I deficiency
- D81.7Major histocompatibility complex class II deficiency
- D81.8Other combined immunodeficiencies
Questions about D81.9
- Is D81.9 a billable ICD-10-CM code?
- Yes. D81.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does D81.9 sit in the tabular list?
- Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Certain disorders involving the immune mechanism (D80-D89).