ICD-10-CM 2027 diagnosis code
E72.4Disorders of ornithine metabolism
E72.4 is a valid, billable ICD-10-CM code for disorders of ornithine metabolism. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Looking up by condition? See ICD-10 code for Ornithinemia, ICD-10 code for Hyperornithinemia.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About E72.4
E72.4 is the ICD-10-CM diagnosis code for disorders of ornithine metabolism. It belongs to category E72 (other disorders of amino-acid metabolism), block E70-E88 (metabolic disorders) and chapter 4 (endocrine, nutritional and metabolic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within E72 (other disorders of amino-acid metabolism), E72.4 is specifically for disorders of ornithine metabolism. Related codes cover disorders of amino-acid transport (E72.0), disorders of sulfur-bearing amino-acid metabolism (E72.1), disorders of urea cycle metabolism (E72.2), disorders of lysine and hydroxylysine metabolism (E72.3), disorders of glycine metabolism (E72.5), other specified disorders of amino-acid metabolism (E72.8) and disorder of amino-acid metabolism, unspecified (E72.9).
Don't report E72.4 together with the conditions in its Excludes1 note: hereditary choroidal dystrophy (H31.2-).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 642 (Inborn and Other Disorders of Metabolism, relative weight 1.3219), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 270.6 (disorders of urea cycle metabolism).
Coding notes
- Hyperammonemia-Hyperornithinemia-Homocitrullinemia syndrome
- Ornithinemia (types I, II)
- Ornithine transcarbamylase deficiency
- hereditary choroidal dystrophy (H31.2-)
Notes that apply from higher levels
Instructions written at a parent level also apply to E72.4.
Broader instructions also apply from E70-E88 Metabolic disorders and Chapter 4: Endocrine, nutritional and metabolic diseases.
Alphabetic index entries
11 entriesTerms in the official ICD-10-CM index that lead to E72.4.
- Deficiency, deficient › ornithine transcarbamylase
- Disorder (of) › metabolism NOS › amino-acid › ornithine
- Disorder (of) › metabolism NOS › ornithine
- Disorder (of) › ornithine metabolism
- Disorder (of) › urea cycle metabolism › ornithine transcarbamylase deficiency
- Disturbance (s) › metabolism › ornithine
- Hyperaminoaciduria › ornithine
- Hyperornithinemia
- Ornithine metabolism disorder
- Ornithinemia (Type I) (Type II)
- Syndrome › hyperammonemia-hyperornithinemia-homocitrullinemia
Codes whose notes reference E72.4
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 10 · Endocrine, Nutritional and Metabolic Diseases and Disorders
ICD-9-CM equivalent
Converter →- 270.6Disorders of urea cycle metabolismapproximate
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about E72.4
Is E72.4 billable?
- Yes. E72.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E72.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E72.4 as a principal diagnosis.
Is E72.4 a CC or MCC?
- E72.4 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.
What DRG does E72.4 group to?
- E72.4 is used in the MS-DRG v44.0 logic for MS-DRG 642 (Inborn and Other Disorders of Metabolism). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for E72.4?
- The CMS General Equivalence Mappings map E72.4 to ICD-9-CM 270.6.