Is D81.89 a billable ICD-10-CM code?

Yes. D81.89 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does D81.89 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).

What cannot be coded together with D81.89?

D81.89 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above D81.89 (D81) and apply to it just the same.

D81.89

D81.89 — Other combined immunodeficiencies

Billable / specific codeICD-10-CM

D81.89 is a billable, specific ICD-10-CM code for other combined immunodeficiencies. It is valid for submission on a claim.

Excludes1 inherited from the categories above D81.89

These are not written on D81.89, but they bind it: a note on a category applies to every code beneath it. Billing D81.89 with anything listed here is a denial.

Written on D81 — Combined immunodeficiencies

autosomal recessive agammaglobulinemia (Swiss type) (D80.0)

Other codes that can never be billed with D81.89

These codes carry an Excludes1 note pointing at D81.89. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading D81.89 alone.

E79Disorders of purine and pyrimidine metabolism

Risk adjustment

D81.89 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

D81.89 is named in 32 Medicare coverage policies — 32 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 D81.89 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 D81.89.

Immunodeficiency›combined›specified type NEC

Code history

D81.89 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share D81.8. If D81.89 is not quite right, the correct code is usually one of these.

Questions about D81.89

Is D81.89 a billable ICD-10-CM code?: Yes. D81.89 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does D81.89 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).
What cannot be coded together with D81.89?: D81.89 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above D81.89 (D81) and apply to it just the same.