2026 ICD-10-CM Diagnosis Code E72.20Disorder of urea cycle metabolism, unspecified
ICD-10-CM Codes›E00–E89›E70-E88›E72
- Billable — Valid for Submission
- Chronic Condition
E72.20 is a billable ICD-10-CM diagnosis code for disorder of urea cycle metabolism, unspecified. 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
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Diazoxide-sensitive diffuse hyperinsulinism
- Disorder of liver co-occurrent and due to disorder of urea cycle
- Disorder of liver due to disorder of amino acid metabolism
- Disorder of lysine and hydroxylysine metabolism
- Disorder of the urea cycle metabolism
- Hyperammonemia
- Hyperammonemic encephalopathy
- Hyperammonemic encephalopathy due to carbonic anhydrase VA deficiency
- Hyperinsulinism and hyperammonemia syndrome
- Hyperlysinemia
- Periodic hyperlysinemia with hyperammonemia
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Hyperammonemia
Type 1 Excludes
- hyperammonemia-hyperornithinemia-homocitrullinemia syndrome E72.4
- transient hyperammonemia of newborn P74.6
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Disorder (of) - See Also: Disease;
- urea cycle metabolism - E72.20
- Disturbance (s) - See Also: Disease;
- metabolism - E88.9
- ammonia - E72.20
- urea cycle - E72.20
- Hyperammonemia (congenital) - E72.20
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Disorder(of)
- urea cycle metabolism
- Disturbance(s)
- metabolism
- ammonia
- Disturbance(s)
- metabolism
- urea cycle
- Hyperammonemia(congenital)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Carbamoyl-Phosphate Synthase I Deficiency Disease
a urea cycle disorder manifesting in infancy as lethargy, emesis, seizures, alterations of muscle tone, abnormal eye movements, and an elevation of serum ammonia. the disorder is caused by a reduction in the activity of hepatic mitochondrial carbamoyl-phosphate synthase (ammonia). (menkes, textbook of child neurology, 5th ed, pp50-1)Hyperammonemia
elevated level of ammonia in the blood. it is a sign of defective catabolism of amino acids or ammonia to urea.Hyperlysinemias
a group of inherited metabolic disorders which have in common elevations of serum lysine levels. enzyme deficiencies of alpha-aminoadipic semialdehyde dehydrogenase and the saccharopine dehydrogenases have been associated with hyperlysinemia. clinical manifestations include mental retardation, recurrent emesis, hypotonia, lethargy, diarrhea, and developmental delay. (from menkes, textbook of child neurology, 5th ed, p56)Rett Syndrome
an inherited neurological developmental disorder that is associated with x-linked inheritance and may be lethal in utero to hemizygous males. the affected female is normal until the age of 6-25 months when progressive loss of voluntary control of hand movements and communication skills; ataxia; seizures; autistic behavior; intermittent hyperventilation; and hyperammonemia appear. (from menkes, textbook of child neurology, 5th ed, p199)Hyperlysinemia
an autosomal recessive inherited condition caused by mutations in the aass gene. it is characterized by elevated levels of the amino acid lysine in the blood. it usually does not cause health problems.
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
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Convert E72.20 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E72.20Overview
Is E72.20 (Disorders of urea cycle metabolism) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report disorder of urea cycle metabolism, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What is the ICD-9 equivalent of E72.20?
Under the General Equivalence Mappings, disorder of urea cycle metabolism, unspecified converts to ICD-9-CM 270.6 (dis urea cycle metabol). 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.
