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ICD-10-CM 2027 diagnosis code

E71.42Carnitine deficiency due to inborn errors of metabolism

✓ Billable / specific

E71.42 is a valid, billable ICD-10-CM code for carnitine deficiency due to inborn errors of metabolism. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

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 E71.42

E71.42 is the ICD-10-CM diagnosis code for carnitine deficiency due to inborn errors of metabolism. It belongs to category E71 (disorders of branched-chain amino-acid metabolism and fatty-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 E71.4 (disorders of carnitine metabolism), E71.42 is specifically for carnitine deficiency due to inborn errors of metabolism. Related codes cover disorder of carnitine metabolism, unspecified (E71.40), primary carnitine deficiency (E71.41), iatrogenic carnitine deficiency (E71.43) and other secondary carnitine deficiency (E71.44).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

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 277.82 (carnitine deficiency due to inborn errors of metabolism).

Coding notes

Code alsoTwo codes may be needed; sequencing depends on circumstances
  • associated inborn error or metabolism

Notes that apply from higher levels

Instructions written at a parent level also apply to E71.42.

› From E71.4 Disorders of carnitine metabolism
Excludes1
  • Muscle carnitine palmitoyltransferase deficiency (E71.314)

Broader instructions also apply from E70-E88 Metabolic disorders and Chapter 4: Endocrine, nutritional and metabolic diseases.

Alphabetic index entries

1 entries

Terms in the official ICD-10-CM index that lead to E71.42.

Codes whose notes reference E71.42

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 →
  • 277.82Carnitine deficiency due to inborn errors of metabolismexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about E71.42

Is E71.42 billable?

Yes. E71.42 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can E71.42 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict E71.42 as a principal diagnosis.

Is E71.42 a CC or MCC?

No. E71.42 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does E71.42 group to?

E71.42 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 E71.42?

The CMS General Equivalence Mappings map E71.42 to ICD-9-CM 277.82.