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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

Defects in post-translational modification of lysosomal enzymes

See Tabular List: E77.0

E77, Disorders of glycoprotein metabolism

E77.0, Defects in post-translational modification of lysosomal enzymes

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

E77.0

Defects in post-translational modification of lysosomal enzymes

Open the shareable code page for E77.0→
billable

Includes

official source
  • Mucolipidosis II [I-cell disease]
  • Mucolipidosis III [pseudo-Hurler polydystrophy]

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

Defects in post-translational modification of lysosomal enzymes

See Tabular List: E77.0

E77, Disorders of glycoprotein metabolism

E77.0, Defects in post-translational modification of lysosomal enzymes

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

E77.0

Defects in post-translational modification of lysosomal enzymes

Open the shareable code page for E77.0→
billable

Includes

official source
  • Mucolipidosis II [I-cell disease]
  • Mucolipidosis III [pseudo-Hurler polydystrophy]

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 23 Other Significant Endocrine and Metabolic Disorders (V24)HCC 41 Lysosomal Storage Disorders (RxHCC)HCC 23 Other Significant Endocrine and Metabolic Disorders (ESRD/PACE)HCC 27 HHS-HCC 27; HHS-HCC 2026 benefit year (HHS-HCC)

RAF Value

V28 RAF source requiredV24: RAF: 0.194RxHCC: RAF: 3.081ESRD/PACE: RAF: 0.036HHS-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 Jess P., CPC

HCC Buddy workflow band

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

MEAT supportaudit cautionsource required

V24

HCC 23

Other Significant Endocrine and Metabolic Disorders

RAF: 0.194

RxHCC

RxHCC 41

Lysosomal Storage Disorders

RAF: 3.081

ESRD/PACE

HCC 23

Other Significant Endocrine and Metabolic Disorders

RAF: 0.036

HHS-HCC

HCC 27

HHS-HCC 27; HHS-HCC 2026 benefit year

RAF: Varies by metal level

MEAT checklist

Reviewed by Jess P., CPC

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 Jess P., CPC

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 Jess P., CPC

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
E77.0Billable

Defects in post-translational modification of lysosomal enzymes

CMS-HCC V24

HCC 23

RAF 0.194

RxHCC

RxHCC 41

RAF 3.081

ESRD/PACE

HCC 23

RAF 0.036

Reviewed by Jess P., CPCFY2026 Apr update

Code

E77.0

V28 HCC

Not mapped

RAF

source required

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