2027 ICD-10-CM Diagnosis Code E77.1Defects in glycoprotein degradation
ICD-10-CM Codes›E00–E89›E70-E88›E77
- Billable — Valid for Submission
- Chronic Condition
E77.1 is a billable ICD-10-CM diagnosis code for defects in glycoprotein degradation. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 642. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.
E77.1 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 23 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 23, ESRD (V21) category 23, ESRD (V24) category 23, and RxHCC Part D (V08) category 41 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
E77.1 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adult fucosidosis
- Aspartylglucosaminuria
- Beta-D-mannosidosis
- Combined deficiency of sialidase AND beta galactosidase
- Deficiency of aspartylglucosaminidase
- Dysmorphic sialidosis
- Dysmorphic sialidosis with renal involvement
- Dysmorphic sialidosis, congenital form
- Dysmorphic sialidosis, infantile form
- Dysmorphic sialidosis, juvenile form
- Fucosidosis
- Infantile fucosidosis
- Juvenile fucosidosis
- Mannosidosis
- Mannosidosis, type I
- Mannosidosis, type II
- Mucolipidosis
- Myoclonic disorder due to sialidosis
- Oligosaccharidosis
- Sialidosis
- Sialidosis type 1
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to E77.1: its own notes plus those printed at block E70-E88 and Chapter 4. A note printed at a category, block or chapter applies to every code under it.
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Aspartylglucosaminuria
- Fucosidosis
- Mannosidosis
- Sialidosis [mucolipidosis I]
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- Ehlers-Danlos syndromes (Q79.6-)
Notes
General instructions on how these codes are used.
- All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name E77.1, its category, or a range that includes it.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Aspartylglucosaminuria E77.1
Fucosidosis E77.1
Mannosidosis E77.1
I E77.1
Sialidosis E77.1
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Aspartylglucosaminuria
a recessively inherited, progressive lysosomal storage disease caused by a deficiency of glycosylasparaginase activity. the lack of this enzyme activity results in the accumulation of n-acetylglucosaminylasparagine (the linkage unit of asparagine-linked glycoproteins) in lysosomes.Fucosidosis
an autosomal recessive lysosomal storage disease caused by a deficiency of alpha-l-fucosidase activity resulting in an accumulation of fucose containing sphingolipids; glycoproteins, and mucopolysaccharides (glycosaminoglycans) in lysosomes. the infantile form (type i) features psychomotor deterioration, muscle spasticity, coarse facial features, growth retardation, skeletal abnormalities, visceromegaly, seizures, recurrent infections, and macroglossia, with death occurring in the first decade of life. juvenile fucosidosis (type ii) is the more common variant and features a slowly progressive decline in neurologic function and angiokeratoma corporis diffusum. type ii survival may be through the fourth decade of life. (from menkes, textbook of child neurology, 5th ed, p87; am j med genet 1991 jan;38(1):111-31)Mannosidase Deficiency Diseases
diseases caused by the loss of one or more enzymes involved in the hydrolysis of mannoside linkages (mannosidases). the defects in enzyme activity are primarily associated with genetic mutation of the genes that codes for a particular mannosidase isoenzyme.Mucolipidoses
a group of inherited metabolic diseases characterized by the accumulation of excessive amounts of acid mucopolysaccharides, sphingolipids, and/or glycolipids in visceral and mesenchymal cells. abnormal amounts of sphingolipids or glycolipids are present in neural tissue. intellectual disability and skeletal changes, most notably dysostosis multiplex, occur frequently. (from joynt, clinical neurology, 1992, ch56, pp36-7)
Patient EducationClinical
Carbohydrate Metabolism Disorders
Metabolism is the process your body uses to make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system (enzymes) break the food parts down into sugars and acids, your body's fuel. Your body can use this fuel right away, or it can store the energy in your body tissues.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert E77.1 to ICD-9-CMHistory
Code HistoryHistory
Questions About E77.1Overview
What is the ICD-10 code for defects in glycoprotein degradation?
The ICD-10-CM code for defects in glycoprotein degradation is E77.1 (sometimes written as E771). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is E77.1 (Disorders of glycoprotein metabolism) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report defects in glycoprotein degradation on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does E77.1 group to?
When defects in glycoprotein degradation is the principal diagnosis on an inpatient stay, it groups to MS-DRG 642 (inborn and Other Disorders of Metabolism), which carries a relative weight of 1.3226. Higher weights mean higher Medicare reimbursement.
Can E77.1 be reported with a code from E34.5?
Not as a rule. The Excludes1 note at block E70-E88, which applies to E77.1, lists "androgen insensitivity syndrome (E34.5-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of E77.1?
Under the General Equivalence Mappings, defects in glycoprotein degradation converts to ICD-9-CM 271.8 (dis carbohydr metab NEC) and 272.7 (lipidoses). The mapping is approximate, so confirm the match fits the documentation.
Does E77.1 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. E77.1 mapped to HCC 23 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V21) category 23 (Other Significant Endocrine and Metabolic Disorders), ESRD (V24) category 23 (Other Significant Endocrine and Metabolic Disorders), and RxHCC Part D (V08) category 41 (Lysosomal Storage Disorders).
