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Alphabetic Index and Tabular path
HCC Buddy public API, FY2026 Apr updateSource load source requiredSource year 2026Updated 2026-04-01

Index trail

Hereditary factor VIII deficiency

See Tabular List: D66

D66, Hereditary factor VIII deficiency

Selected code, source checked for the selected effective period

Commonly confused codes

official source

Not listed for this effective period.

Code details and official notes

D66

Hereditary factor VIII deficiency

Open the shareable code page for D66→
billableHCC mapped

Includes

official source
  • Classical hemophilia
  • Deficiency factor VIII (with functional defect)
  • Hemophilia NOS
  • Hemophilia A

Excludes 1

official source
  • factor VIII deficiency with vascular defect (D68.0-)

Excludes 2

official source

No Excludes 2 note is listed in this source payload.

Code First

official source

Not listed for this effective period.

Use Additional

official source

Not listed for this effective period.

Code Also

official source

Not listed for this effective period.

7th character

official source

Not listed for this code in the selected Tabular payload.

Placeholder X

official source

Not listed for this code in the selected Tabular payload.

Laterality

official source

No laterality instruction is listed for this code in the selected Tabular payload.

Effective period

source required
  • FY2026 Apr update
  • Source year 2026
  • Updated 2026-04-01
  • HCC Buddy public API
HCC Buddy
HCC Buddy
Alphabetic Index and Tabular path
HCC Buddy public API, FY2026 Apr updateSource load source requiredSource year 2026Updated 2026-04-01

Index trail

Hereditary factor VIII deficiency

See Tabular List: D66

D66, Hereditary factor VIII deficiency

Selected code, source checked for the selected effective period

Commonly confused codes

official source

Not listed for this effective period.

Code details and official notes

D66

Hereditary factor VIII deficiency

Open the shareable code page for D66→
billableHCC mapped

Includes

official source
  • Classical hemophilia
  • Deficiency factor VIII (with functional defect)
  • Hemophilia NOS
  • Hemophilia A

Excludes 1

official source
  • factor VIII deficiency with vascular defect (D68.0-)

Excludes 2

official source

No Excludes 2 note is listed in this source payload.

Code First

official source

Not listed for this effective period.

Use Additional

official source

Not listed for this effective period.

Code Also

official source

Not listed for this effective period.

7th character

official source

Not listed for this code in the selected Tabular payload.

Placeholder X

official source

Not listed for this code in the selected Tabular payload.

Laterality

official source

No laterality instruction is listed for this code in the selected Tabular payload.

Effective period

source required
  • FY2026 Apr update
  • Source year 2026
  • Updated 2026-04-01
  • HCC Buddy public API
HCC Buddy Insights

HCC Mapping

HCC 111 Hemophilia, Male (V28)HCC 46 Severe Hematological Disorders (V24)RxHCC source requiredHCC 46 Severe Hematological Disorders (ESRD/PACE)HHS-HCC source required or member context needed for selected effective period (HHS-HCC)

RAF Value

V28: RAF: 4.639V24: RAF: 1.372RxHCC RAF source requiredESRD/PACE: RAF: 0.223HHS-HCC RAF source required

Model Period

FY2026 Apr update

Source

source required

Audit Caution

Close codes need documentation support before selection. Do not assume relationships.
Reviewed by the HCC Buddy Coding Team

HCC Buddy workflow band

HCC mapping, RAF, MEAT, source trail, and audit caution stay in view.

MEAT supportaudit cautionsource required

V28

HCC 111

Hemophilia, Male

RAF: 4.639

V24

HCC 46

Severe Hematological Disorders

RAF: 1.372

ESRD/PACE

HCC 46

Severe Hematological Disorders

RAF: 0.223

HHS-HCC

source required

HHS-HCC source required or member context needed for selected effective period

RAF: source required

MEAT checklist

Reviewed by the HCC Buddy Coding Team

Monitor, Evaluate, Assess, or Treat must be supported in the provider note.

HCC Buddy guidance, not official ICD-10-CM text.

Audit caution

Reviewed by the HCC Buddy Coding Team

Close codes need documentation support before selection. Do not assume relationships.

HCC Buddy guidance, not official ICD-10-CM text.

Reviewer sign-off

Reviewed by the HCC Buddy Coding Team

MEAT, documentation support, audit cautions, and close-code guidance are reviewed and approved for this effective period.

HCC Buddy enrichment is separate from official source text.

Last updated: April 1, 2026 · Not a substitute for official coding guidelines. No PHI or patient data.
HCC Buddy Code Card
FY 2026 Apr update
D66Billable

Hereditary factor VIII deficiency

CMS-HCC V28

HCC 111

RAF 4.639

CMS-HCC V24

HCC 46

RAF 1.372

ESRD/PACE

HCC 46

RAF 0.223

Reviewed by the HCC Buddy Coding TeamFY2026 Apr update

Code

D66

V28 HCC

HCC 111

RAF

4.639

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