D81 — Combined immunodeficiencies
Is D81 billable?
No — D81 is a non-billable header code. D81 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 17 billable codes beneath D81.
Billable codes under this header
- 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
- D81.4Nezelof's syndrome
- D81.5Purine nucleoside phosphorylase [PNP] deficiency
- D81.6Major histocompatibility complex class I deficiency
- D81.7Major histocompatibility complex class II deficiency
- D81.9Combined immunodeficiency, unspecified
- D81.30Adenosine deaminase deficiency, unspecified
- D81.31Severe combined immunodeficiency due to adenosine deaminase deficiency
- D81.32Adenosine deaminase 2 deficiency
- D81.39Other adenosine deaminase deficiency
- D81.82Activated Phosphoinositide 3-kinase Delta Syndrome [APDS]
- D81.89Other combined immunodeficiencies
- D81.810Biotinidase deficiency
- D81.818Other biotin-dependent carboxylase deficiency
- D81.819Biotin-dependent carboxylase deficiency, unspecified
D81 at a glance
| Code | D81 |
|---|---|
| Description | Combined immunodeficiencies |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with D81 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- autosomal recessive agammaglobulinemia (Swiss type) (D80.0)
Excludes1 — never code together — inherited from D80-D89
The conditions below can never be reported together with D81 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 3
The conditions below are not part of D81, but a patient may have both at the same time. When documentation supports it, D81 and the excluded code may both be reported.
- autoimmune disease (systemic) NOS (M35.9)
- certain conditions originating in the perinatal period (P00-P96)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- human immunodeficiency virus [HIV] disease (B20)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Excludes2 — not included here — inherited from D80-D89
The conditions below are not part of D81, but a patient may have both at the same time. When documentation supports it, D81 and the excluded code may both be reported.
- human immunodeficiency virus [HIV] disease (B20)
What codes fall under D81? (10)
- 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] deficiencynot billable
- 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 immunodeficienciesnot billable
- D81.9Combined immunodeficiency, unspecified
How long has D81 existed?
D81 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with D81?
ICD-10-CM declares these codes mutually exclusive with D81 — exactly one of each pair can be correct for a given encounter.