ICD-10-CM
ICD-10 code for Immunodeficiency combined: D81.9
The ICD-10-CM index points "Immunodeficiency combined" to D81.9, Combined immunodeficiency, unspecified. D81.9 is a billable code.
Source: CDC ICD-10-CM FY2027 Alphabetic Index file dated June 16, 2026. Publisher page
Run it in Rivvi
Check every code on your export
Upload a claims or problem-list export. Rivvi flags codes that are not billable, replaced, or unspecified when a specific code exists.
Check my exportFree to start. Opens Rivvi, the AI workspace for healthcare teams.
Index subterms
A header groups codes and is not billed. A billable code is one you can report.
More specific codes in D81
A header groups codes and is not billed. A billable code is one you can report.
- D81Combined immunodeficienciesHeader
- D81.0Severe combined immunodeficiency [SCID] with reticular dysgenesisBillable
- D81.1Severe combined immunodeficiency [SCID] with low T- and B-cell numbersBillable
- D81.2Severe combined immunodeficiency [SCID] with low or normal B-cell numbersBillable
- D81.3Adenosine deaminase [ADA] deficiencyHeader
- D81.30Adenosine deaminase deficiency, unspecifiedBillable
- D81.31Severe combined immunodeficiency due to adenosine deaminase deficiencyBillable
- D81.32Adenosine deaminase 2 deficiencyBillable
- D81.39Other adenosine deaminase deficiencyBillable
- D81.4Nezelof's syndromeBillable
- D81.5Purine nucleoside phosphorylase [PNP] deficiencyBillable
- D81.6Major histocompatibility complex class I deficiencyBillable
- D81.7Major histocompatibility complex class II deficiencyBillable
- D81.8Other combined immunodeficienciesHeader
- D81.81Biotin-dependent carboxylase deficiencyHeader
- D81.810Biotinidase deficiencyBillable
- D81.818Other biotin-dependent carboxylase deficiencyBillable
- D81.819Biotin-dependent carboxylase deficiency, unspecifiedBillable
- D81.82Activated Phosphoinositide 3-kinase Delta Syndrome [APDS]Billable
- D81.89Other combined immunodeficienciesBillable
- D81.9Combined immunodeficiency, unspecifiedBillable
Excludes1
Excludes1 means these codes are not reported together.
From D81. A note on a category applies to every code under it.
Related conditions
Related pages
- D81.9 code detailsNotes, nearby codes, CMS-HCC group
- Category D81Every code under it
- Chapter 3Diseases of the blood and blood-forming organs
- ICD-10 codes by conditionA to Z
- Check a list of ICD-10 codes
- Denial code CO-11Diagnosis does not support the procedure
- Denial code CO-146Diagnosis invalid for the date of service
- HCPCS Level II code lookup
Questions
What is the ICD-10 code for Immunodeficiency combined?
The ICD-10-CM index points "Immunodeficiency combined" to D81.9, Combined immunodeficiency, unspecified. D81.9 is a billable code.
Is D81.9 billable?
Yes. D81.9 is a billable code in the FY2027 ICD-10-CM file. Use a more specific code when the record documents one.
What documentation notes apply to D81.9?
The CDC tabular list gives 1 Excludes1 note (not coded together) for D81.9 and the categories above it. They are listed on this page.
What chapter is D81.9 in?
Chapter 3. Diseases of the blood and blood-forming organs.
When do ICD-10-CM codes change?
Every October 1, with the new fiscal year file. Some years add April 1 updates. This page uses the FY2027 file, effective October 1, 2026.