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HCC Buddy Code Book

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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

Lymphocyte function antigen-1 [LFA-1] defect

See Tabular List: D84.0

D84, Other immunodeficiencies

D84.0, Lymphocyte function antigen-1 [LFA-1] defect

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

D84.0

Lymphocyte function antigen-1 [LFA-1] defect

Open the shareable code page for D84.0
billable

Includes

official source

Not listed for this effective period.

Excludes 1

official source

No Excludes 1 note is listed in this source payload.

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

Lymphocyte function antigen-1 [LFA-1] defect

See Tabular List: D84.0

D84, Other immunodeficiencies

D84.0, Lymphocyte function antigen-1 [LFA-1] defect

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

D84.0

Lymphocyte function antigen-1 [LFA-1] defect

Open the shareable code page for D84.0
billable

Includes

official source

Not listed for this effective period.

Excludes 1

official source

No Excludes 1 note is listed in this source payload.

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

V28 source requiredHCC 47 Disorders of Immunity (V24)HCC 99 Immunodeficiencies (RxHCC)HCC 47 Disorders of Immunity (ESRD/PACE)HCC 74 HHS-HCC 74; HHS-HCC 2026 benefit year (HHS-HCC)

RAF Value

V28 RAF source requiredV24: RAF: 0.665RxHCC: RAF: 0.943ESRD/PACE: RAF: 0.078HHS-HCC: RAF: Varies by metal level

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

V24

HCC 47

Disorders of Immunity

RAF: 0.665

RxHCC

RxHCC 99

Immunodeficiencies

RAF: 0.943

ESRD/PACE

HCC 47

Disorders of Immunity

RAF: 0.078

HHS-HCC

HCC 74

HHS-HCC 74; HHS-HCC 2026 benefit year

RAF: Varies by metal level

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
D84.0Billable

Lymphocyte function antigen-1 [LFA-1] defect

CMS-HCC V24

HCC 47

RAF 0.665

RxHCC

RxHCC 99

RAF 0.943

ESRD/PACE

HCC 47

RAF 0.078

Reviewed by the HCC Buddy Coding TeamFY2026 Apr update

Code

D84.0

V28 HCC

Not mapped

RAF

source required

Compare tray

Add close codes to compare documentation differences.