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E71.41 ICD-10-CM Code: Primary carnitine deficiency

E71.41 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · free HCC coding tools

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

E71.41

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

Primary carnitine deficiency

A rare genetic condition where the body cannot produce enough carnitine, a substance essential for converting fats into energy, due to inherited genetic mutations.

Buddy the Bee presenting code insight

Buddy Insight

Primary carnitine deficiency (systemic carnitine deficiency) is caused by mutations in the SLC22A5 gene encoding the carnitine transporter OCTN2, resulting in excessive urinary carnitine loss and critically low plasma carnitine levels.

CMS-HCC V28

N/A

Not mapped

CMS-HCC V24

HCC 23

RAF 0.194

ACA/HHS

HCC 29

Varies by metal level

ESRD/PACE

HCC 23

RAF 0.036

RXHCC

HCC 43

RAF 0.063

Code Book Path

Official
E71Disorders of branched-chain amino-acid metabolism and fatty-acid metabolism
E71.4Disorders of carnitine metabolism
E71.41Primary carnitine deficiency

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for E71.41 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E71.41 in this effective period.

Related Child Codes

Official
E71.40Disorder of carnitine metabolism, unspecified
E71.42Carnitine deficiency due to inborn errors of metabolism
E71.43Iatrogenic carnitine deficiency
E71.44Other secondary carnitine deficiency

Includes

Official

ICD-10-CM does not list Includes notes for E71.41 in this effective period.

Excludes 1

Official
  • Muscle carnitine palmitoyltransferase deficiency (E71.314)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E71.41 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E71.41 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E71.41 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
Document plasma carnitine levels (typically very low free carnitine <5 micromol/L), genetic testing confirming SLC22A5 mutations, echocardiogram findings, clinical presentation, and carnitine supplementation dosage and response.
Record whether identified through newborn screening or clinical presentation.

MEAT Support

HCC Buddy guidance
Document plasma carnitine levels (typically very low free carnitine <5 micromol/L), genetic testing confirming SLC22A5 mutations, echocardiogram findings, clinical presentation, and carnitine supplementation dosage and response.
Record whether identified through newborn screening or clinical presentation.

Audit Caution

HCC Buddy guidance
Primary carnitine deficiency refers specifically to the genetic carnitine transporter defect, not carnitine deficiency secondary to other metabolic disorders or medications.
Ensure documentation distinguishes primary from secondary causes.

Common Mistakes

HCC Buddy guidance
E71.40 (Disorder of carnitine metabolism, unspecified) which lacks specificity
E71.42 (Carnitine deficiency due to inborn errors of metabolism) which is secondary to another metabolic disorder
E71.448 (Other secondary carnitine deficiency) for acquired causes.

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 E71.41 an HCC code?

Yes. E71.41 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.

Code
E71.41
Description
Primary carnitine deficiency
HCC (V28)
No CMS-HCC V28 mapping
RAF
Billable
Yes
Payment year
2026

HCC Category Mapping

V24HCC 23, Other Significant Endocrine and Metabolic Disorders
0.194
ESRDHCC 23, Other Significant Endocrine and Metabolic Disorders
0.036
RxHCCHCC 43, Other Significant Endocrine and Metabolic Disorders
0.063

Each model's RAF is its CMS base weight for that model's standard population, so 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 segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work E71.41 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E71.41

For E71.41 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

  • 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

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E71.41 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E71.41 is the ICD-10-CM diagnosis code for primary carnitine deficiency. A rare genetic condition where the body cannot produce enough carnitine, a substance essential for converting fats into energy, due to inherited genetic mutations. E71.41 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).

Under the older CMS-HCC V24 model, E71.41 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.194. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Document whether this is systemic carnitine deficiency or muscle-specific carnitine deficiency. Because E71.41 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E71.41 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Document whether this is systemic carnitine deficiency or muscle-specific carnitine deficiency
  • Note any cardiac involvement (cardiomyopathy) or muscle weakness that may require additional codes

Clinical Significance

Primary carnitine deficiency (systemic carnitine deficiency) is caused by mutations in the SLC22A5 gene encoding the carnitine transporter OCTN2, resulting in excessive urinary carnitine loss and critically low plasma carnitine levels. Without treatment, patients face risk of hypoketotic hypoglycemia, cardiomyopathy, and sudden death. Lifelong oral carnitine supplementation is highly effective and dramatically improves outcomes.

Documentation Requirements

  • Document plasma carnitine levels (typically very low free carnitine <5 micromol/L), genetic testing confirming SLC22A5 mutations, echocardiogram findings, clinical presentation, and carnitine supplementation dosage and response.
  • Record whether identified through newborn screening or clinical presentation.

Commonly Confused Codes

  • E71.40 (Disorder of carnitine metabolism, unspecified) which lacks specificity
  • E71.42 (Carnitine deficiency due to inborn errors of metabolism) which is secondary to another metabolic disorder
  • E71.448 (Other secondary carnitine deficiency) for acquired causes.

Child Codes

Code Hierarchy

Because E71.41 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

Work E71.41 in HCC Buddy

Open E71.41 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.