2026 ICD-10-CM Diagnosis Code E77.0Defects in post-translational modification of lysosomal enzymes

ICD-10-CM Codes›E00–E89›E70-E88›E77

ICD-10-CM E77.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E77.0 is a billable ICD-10-CM diagnosis code for defects in post-translational modification of lysosomal enzymes. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as defect in post-translational modification of lysosomal enzymes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.

Code Identity

ICD-10-CM Code
E77.0
Billable Status
Yes — Valid for Submission
Code Describes
Defects in post-translational modification of lysosomal enzymes
Short Description
Defects in post-translational mod of lysosomal enzymes
Parent Code
E77
Disorders of glycoprotein metabolism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE70-E88Metabolic disorders
CategoryE77Disorders of glycoprotein metabolism
This CodeE77.0Defects in post-translational modification of lysosomal enzymes

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Defect in post-translational modification of lysosomal enzymes
  • I-cell disease
  • Mucolipidosis
  • Pseudo-Hurler polydystrophy

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Mucolipidosis II I-cell disease
  • Mucolipidosis III pseudo-Hurler polydystrophy

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Defect, defective
      • lysosomal enzyme, post-translational modification
    • Defect, defective
      • modification, lysosomal enzymes, post-translational
    • Disease, diseased
      • I-cell
    • Disease, diseased
      • pseudo-Hurler's
    • Mucolipidosis
      • II, III
    • Polydystrophy, pseudo-Hurler
    • Pseudo-Hurler's polydystrophy

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END016
Other specified and unspecified nutritional and metabolic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • I-Cell Disease|Inclusion-cell Disease|Mucolipidosis Type II

    an inherited lysosomal storage disease characterized by the presence of dense intracytoplasmic inclusions in mesenchymal cells, especially fibroblasts. signs and symptoms include developmental delay, psychomotor deterioration, and growth failure.

  • Mucolipidosis

    a group of inherited lysosomal storage diseases characterized by accumulation of lipids and carbohydrates in the tissues, resulting in mental disabilities and skeletal malformations.

  • Mucolipidosis Type III Gamma|Mucolipidosis III Gamma

    an autosomal recessive condition caused by mutation(s) in the gnptag gene, encoding n-acetylglucosamine-1-phosphotransferase subunit gamma. it is characterized by a slowing of the growth rate in childhood, joint stiffness, mild cognitive impairment, and cardiorespiratory insufficiency.

  • Mucolipidosis Type IIIA

    a lysosomal storage disease characterized by multiple bone formation abnormalities, progressive joint stiffness, developmental abnormalities, hearing loss, hepatosplenomegaly, increased acne, enlarged tongue, and cornea clouding due to accumulation of lipid substances.

  • Mucolipidosis Type IV|Mucolipidosis IV

    an autosomal recessive lysosomal storage disease caused by mutations in the mcoln1 gene. it is characterized by psychomotor developmental delays and ophthalmologic abnormalities.

  • Neuraminidase Deficiency|Mucolipidosis I|Sialidosis Type II

    an autosomal recessive inherited lysosomal storage disease characterized by excessive intracellular accumulation and urinary excretion of sialic acid associated with neuraminidase deficiency.

  • MCOLN1 wt Allele|MG-2|ML1|ML4|MLIV|MST080|MSTP080|Mucolipidosis Type IV Gene|Mucolipin 1 Gene|Mucolipin TRP Cation Channel 1 wt Allele|TRP-ML1|TRPM-L1|TRPML1|Transient Receptor Potential Cation Channel Mucolipin Subfamily Member 1 Gene|Transient Receptor Potential Cation Channel, Mucolipin Subfamily, Member 1 Gene|Transient Receptor Potential Mucolipin 1 Gene

    human mcoln1 wild-type allele is located in the vicinity of 19p13.2 and is approximately 11 kb in length. this allele, which encodes mucolipin-1 protein, plays a role in the regulation of membrane trafficking events and of cation homeostasis. mutation of the gene is associated with mucolipidosis iv.

Patient EducationClinical

Metabolic Disorders

Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E77.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
272.7 Lipidoses
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E77.0Overview

Is E77.0 (Disorders of glycoprotein metabolism) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report defects in post-translational modification of lysosomal enzymes on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of E77.0?

Under the General Equivalence Mappings, defects in post-translational modification of lysosomal enzymes converts to ICD-9-CM 272.7 (lipidoses). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.