What is ICD-10 code E75.27?

E75.27 is the ICD-10-CM diagnosis code for Pelizaeus-Merzbacher disease. A rare inherited neurological disorder affecting the development and maintenance of myelin (the protective coating around nerve fibers), causing progressive weakness and loss of motor control. E75.27 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E75.27 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E75.27 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E75.27 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does E75.27 map to under V28?

E75.27 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for E75.27?

E75.27 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for E75.27?

E75.27 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

What documentation supports E75.27?

Document the specific type: classic, connatal, or transitional form to support medical necessity Link to associated neurological complications such as spasticity or developmental delays E75.27 is not a CMS-HCC V28 payment code in the verified current source, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

Can E75.27 be a primary diagnosis?

Yes. E75.27 carries no code-first instruction in the FY2026 tabular, so it can be the first-listed diagnosis when it is the condition chiefly responsible for the encounter and the note supports it, and it can also be reported as a secondary diagnosis. For risk adjustment the order does not matter; the V28 category is the same either way.

Which codes cannot be reported with E75.27?

The Excludes1 note that applies to E75.27 lists transitory endocrine and metabolic disorders specific to newborn (P70-P74); androgen insensitivity syndrome (E34.5-); congenital adrenal hyperplasia (E25.0); hemolytic anemias attributable to enzyme disorders (D55.-); and 5 more (see the notes on this page). An Excludes1 condition is not reported together with E75.27; report one or the other, unless the two conditions are unrelated, which the ICD-10-CM Official Guidelines (Section I.A.12.a) allow. The Excludes2 note lists Ehlers-Danlos syndromes (Q79.6-); those are separate conditions that may be reported together with E75.27 when both are documented.

2026 ICD-10-CM E75.27: Pelizaeus-Merzbacher disease

E75.27 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupE75.27

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Metabolic disorders (E70-E88)

E75.27

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Pelizaeus-Merzbacher disease

A rare inherited neurological disorder affecting the development and maintenance of myelin (the protective coating around nerve fibers), causing progressive weakness and loss of motor control.

Buddy Insight

Pelizaeus-Merzbacher disease is an X-linked hypomyelinating disorder caused by PLP1 gene mutations affecting proteolipid protein production, which is essential for myelin formation.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 119

HHS-HCC 119 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 52

Dementia Without Complication

Code-level coefficient reference

RXHCC

Mapped

HCC 41

Lysosomal Storage Disorders

Code-level coefficient reference

Code Book Path

Official

E75Disorders of sphingolipid metabolism and other lipid storage disorders E75.2Other sphingolipidosis E75.27Pelizaeus-Merzbacher disease

Inclusion Terms

Official

No inclusion terms are included in this display for E75.27. Check the code and parent instructions in the Code Book.

Excludes 2

Official

Ehlers-Danlos syndromes (Q79.6-)Inherited from E70-E88

Related Codes

Official

E75.21Fabry (-Anderson) disease E75.22Gaucher disease E75.23Krabbe disease E75.24Niemann-Pick disease E75.25Metachromatic leukodystrophy

Includes

Official

No Includes notes are included in this display for E75.27. Check the code and parent instructions in the Code Book.

Excludes 1

Official

transitory endocrine and metabolic disorders specific to newborn (P70-P74)Inherited from E00-E89, E70-E88, E75, E75.2
androgen insensitivity syndrome (E34.5-)Inherited from E00-E89, E70-E88, E75, E75.2
congenital adrenal hyperplasia (E25.0)Inherited from E00-E89, E70-E88, E75, E75.2
hemolytic anemias attributable to enzyme disorders (D55.-)Inherited from E00-E89, E70-E88, E75, E75.2
Marfan syndrome (Q87.4-)Inherited from E00-E89, E70-E88, E75, E75.2
5-alpha-reductase deficiency (E29.1)Inherited from E00-E89, E70-E88, E75, E75.2
mucolipidosis, types I-III (E77.0-E77.1)Inherited from E00-E89, E70-E88, E75, E75.2
Refsum's disease (G60.1)Inherited from E00-E89, E70-E88, E75, E75.2
adrenoleukodystrophy [Addison-Schilder] (E71.528)Inherited from E00-E89, E70-E88, E75, E75.2

Code First

Official

No Code First sequencing instructions are included in this display for E75.27. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for E75.27. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for E75.27. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed diagnosis of Pelizaeus-Merzbacher disease

PLP1 gene mutation analysis (duplications, point mutations, or deletions)

Brain MRI showing diffuse hypomyelination pattern

Form specification: classic (Type I), connatal (Type II), or transitional

MEAT Support

HCC Buddy guidance

Confirmed diagnosis of Pelizaeus-Merzbacher disease

PLP1 gene mutation analysis (duplications, point mutations, or deletions)

Brain MRI showing diffuse hypomyelination pattern

Form specification: classic (Type I), connatal (Type II), or transitional

Audit Caution

HCC Buddy guidance

Confusing Pelizaeus-Merzbacher disease (hypomyelinating) with metachromatic leukodystrophy or Krabbe disease (demyelinating)

Missing the characteristic nystagmus in infancy that is an early sign of PMD

Not recognizing PMD-like disease caused by GJC2 mutations (previously called PMD2) as a distinct entity

Failing to code spasticity, developmental delay, and other neurological complications separately

Common Mistakes

HCC Buddy guidance

E75.25 — Metachromatic leukodystrophy: a demyelinating disorder (myelin is formed then destroyed), not hypomyelinating

E75.23 — Krabbe disease: demyelinating leukodystrophy with different pathogenesis

E75.28 — Canavan disease: different leukodystrophy with spongy degeneration

G37.0 — Diffuse sclerosis of central nervous system: acquired demyelination, not genetic hypomyelination

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is E75.27 an HCC code?

E75.27 is not in the CMS-HCC V28 or V24 community payment model. E75.27 has a separate mapping under the CMS-HCC ESRD model (HCC 52 (Dementia Without Complication)) and the Part D RxHCC model (HCC 41 (Lysosomal Storage Disorders)); the applicable result needs member context. E75.27 also appears in the HHS-HCC commercial risk model (HCC 119 (HHS-HCC 119 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping.

Code: E75.27
Description: Pelizaeus-Merzbacher disease
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

ESRDHCC 52, Dementia Without Complication

Not separately weighted

RxHCCHCC 41, Lysosomal Storage Disorders

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work E75.27 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for E75.27

For E75.27, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

Get the V28 mapping + MEAT cheat sheet

One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

E75.27 is the ICD-10-CM diagnosis code for pelizaeus-merzbacher disease. A rare inherited neurological disorder affecting the development and maintenance of myelin (the protective coating around nerve fibers), causing progressive weakness and loss of motor control. E75.27 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).

E75.27 has no mapping under the CMS-HCC V28 or V24 community payment models. E75.27 has a separate mapping under the CMS-HCC ESRD model (HCC 52 (Dementia Without Complication)) and the Part D RxHCC model (HCC 41 (Lysosomal Storage Disorders)); the applicable result needs member context. E75.27 also appears in the HHS-HCC commercial risk model (HCC 119 (HHS-HCC 119 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

Document the specific type: classic, connatal, or transitional form to support medical necessity.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for E75.27 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Document the specific type: classic, connatal, or transitional form to support medical necessity
•Link to associated neurological complications such as spasticity or developmental delays

Clinical Significance

Pelizaeus-Merzbacher disease is an X-linked hypomyelinating disorder caused by PLP1 gene mutations affecting proteolipid protein production, which is essential for myelin formation. Unlike demyelinating leukodystrophies, myelin is never properly formed. Patients develop nystagmus, spasticity, ataxia, and cognitive impairment. The classic form allows survival into adulthood, while the connatal form is more severe with limited life expectancy.

Documentation Requirements

✓Confirmed diagnosis of Pelizaeus-Merzbacher disease
✓PLP1 gene mutation analysis (duplications, point mutations, or deletions)
✓Brain MRI showing diffuse hypomyelination pattern
✓Form specification: classic (Type I), connatal (Type II), or transitional
✓Neurological assessment including nystagmus, spasticity, and developmental status
✓X-linked inheritance pattern documentation and family history

Commonly Confused Codes

•E75.25: Metachromatic leukodystrophy: a demyelinating disorder (myelin is formed then destroyed), not hypomyelinating
•E75.23: Krabbe disease: demyelinating leukodystrophy with different pathogenesis
•E75.28: Canavan disease: different leukodystrophy with spongy degeneration
•G37.0: Diffuse sclerosis of central nervous system: acquired demyelination, not genetic hypomyelination
•G11.1: Early-onset cerebellar ataxia: ataxia is a feature of PMD, not the primary diagnosis