D81.2

Severe combined immunodeficiency [SCID] with low or normal B-cell numbers

FY2027Chapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism/D80–D89 Certain disorders involving the immune mechanism

BillableComplete code, valid to report

D81.2 (also written D812) is a billable ICD-10-CM diagnosis code for severe combined immunodeficiency [SCID] with low or normal B-cell numbers. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 17 codes in category D81 (Combined immunodeficiencies). The Alphabetic Index lists it under 1 entry. Its coding notes include 3 Excludes1 entries and 10 Excludes2 entries.

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from D81 Combined immunodeficiencies
  • autosomal recessive agammaglobulinemia (Swiss type) (D80.0)
Also from chapter/block level (2 notes)
Inherited from D80–D89 Certain disorders involving the immune mechanism
  • autoimmune disease (systemic) NOS (M35.9)
  • functional disorders of polymorphonuclear neutrophils (D71-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (10 notes)
Inherited from D80–D89 Certain disorders involving the immune mechanism
  • human immunodeficiency virus [HIV] disease (B20)
Inherited from Chapter 3 Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
  • 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)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 44 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Includes

Further defines or gives examples of the content of the category.

Also from chapter/block level (3 notes)
Inherited from D80–D89 Certain disorders involving the immune mechanism
  • defects in the complement system
  • immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
  • sarcoidosis

Alphabetic Index terms

Terms the official Alphabetic Index lists for this code. 1 entry