2026 ICD-10-CM Diagnosis Code E70.0Classical phenylketonuria

ICD-10-CM Codes›E00–E89›E70-E88›E70

ICD-10-CM E70.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E70.0 is a billable ICD-10-CM diagnosis code for classical phenylketonuria. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). 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
E70.0
Billable Status
Yes — Valid for Submission
Code Describes
Classical phenylketonuria
Short Description
Classical phenylketonuria
Same as the full description in the CMS dataset.
Parent Code
E70
Disorders of aromatic amino-acid metabolism

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE70-E88Metabolic disorders
CategoryE70Disorders of aromatic amino-acid metabolism
This CodeE70.0Classical phenylketonuria

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Classical phenylketonuria
  • Classical phenylketonuria with partial deficiency of phenylalanine hydroxylase
  • Classical phenylketonuria with total deficiency of phenylalanine hydroxylase
  • Phenylketonuria

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.

    • Disorder(of)
      • metabolism NOS
        • amino-acid
          • aromatic
            • hyperphenylalaninemia
              • classical phenylketonuria
    • Følling's disease
    • Oligophrenia
      • phenylpyruvic
    • Phenylketonuria
      • classical

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

Patient EducationClinical

Phenylketonuria

Phenylketonuria (PKU) is a type of amino acid metabolism disorder. It is inherited. If you have it, your body can't process phenylalanine (Phe). Phe is an amino acid, a building block of proteins. It is in almost all foods. If your Phe level gets too high, it can damage your brain and cause severe intellectual disability.

Read the full article at MedlinePlus

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

Convert E70.0 to ICD-9-CMHistory

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

ICD-9-CM
270.1 Phenylketonuria - pku
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 E70.0Overview

Is E70.0 (Disorders of aromatic amino-acid metabolism) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report classical phenylketonuria on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of E70.0?

Under the General Equivalence Mappings, classical phenylketonuria converts to ICD-9-CM 270.1 (phenylketonuria - pku). 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.