ICD-10-CM 2027
ICD-10 code for Subhemophilia
From the official ICD-10-CM alphabetic index entry “Subhemophilia”. Page updated September 29, 2026.
About coding Subhemophilia
The ICD-10-CM code for Subhemophilia is D66 (Hereditary factor VIII deficiency).
Don't report D66 together with the conditions in its Excludes1 note: factor VIII deficiency with vascular defect (D68.0-).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 813 (Coagulation Disorders, relative weight 1.5257), in MDC 16 (Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Don't confuse with (Excludes1 for D66)
- factor VIII deficiency with vascular defect (D68.0-)
Common questions about Subhemophilia ICD-10 codes
What is the ICD-10 code for Subhemophilia?
- D66 — Hereditary factor VIII deficiency.
Is D66 billable?
- Yes. D66 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can D66 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict D66 as a principal diagnosis.
Is D66 a CC or MCC?
- D66 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.