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E43 ICD-10-CM Code: Unspecified severe protein-calorie malnutrition

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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Malnutrition (E40-E46)

E43

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

Unspecified severe protein-calorie malnutrition

Severe malnutrition due to inadequate protein and calories when the specific type (kwashiorkor vs. marasmus) cannot be determined.

Buddy the Bee presenting code insight

Buddy Insight

Unspecified severe protein-calorie malnutrition indicates that a patient has documented severe malnutrition but the clinical picture does not clearly distinguish between kwashiorkor and marasmus, or the provider has not specified the type.

CMS-HCC V28

N/A

—

Not mapped

CMS-HCC V24

HCC 21

RAF 0.455

ACA/HHS

HCC 23

Varies by metal level

ESRD/PACE

HCC 21

RAF 0.068

RXHCC

N/A

—

Not mapped

Code Book Path

Official
E4Malnutrition (E40-E46)
E43Unspecified severe protein-calorie malnutrition

Inclusion Terms

Official
  • Starvation edema

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E43 in this effective period.

Related Child Codes

Official

ICD-10-CM does not list child codes under E43 for this display context.

Includes

Official

ICD-10-CM does not list Includes notes for E43 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for E43 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E43 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E43 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E43 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
Documentation should include evidence of severe malnutrition such as body mass index below 16, severe muscle wasting, laboratory markers (albumin below 2.5 g/dL, prealbumin below 5 mg/dL), and functional impairment.
The provider should attempt to specify whether edema is present (suggesting kwashiorkor) or absent (suggesting marasmus) for more specific coding.
Underlying cause and treatment plan must be documented.

MEAT Support

HCC Buddy guidance
Documentation should include evidence of severe malnutrition such as body mass index below 16, severe muscle wasting, laboratory markers (albumin below 2.5 g/dL, prealbumin below 5 mg/dL), and functional impairment.
The provider should attempt to specify whether edema is present (suggesting kwashiorkor) or absent (suggesting marasmus) for more specific coding.
Underlying cause and treatment plan must be documented.

Audit Caution

HCC Buddy guidance
This code should prompt a provider query for more specific documentation to enable assignment of E40, E41, or E
Do not assign severe malnutrition without supporting clinical evidence such as markedly low body mass index, severe laboratory derangements, or documented severe wasting. Avoid defaulting to this code when mild or moderate malnutrition is a more accurate characterization.

Common Mistakes

HCC Buddy guidance
E40 (Kwashiorkor), E41 (Nutritional marasmus), and E42 (Marasmic kwashiorkor) are preferred when the type can be determined.
E44.0 (Moderate protein-calorie malnutrition) and E44.1 (Mild protein-calorie malnutrition) indicate less severe forms.
E46 (Unspecified protein-calorie malnutrition) does not specify severity.
Query the provider to determine if E40-E42 can be assigned instead.

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 E43 an HCC code?

Yes. E43 maps to Protein-Calorie Malnutrition under the V24 model but is not retained in V28.

Code
E43
Description
Unspecified severe protein-calorie malnutrition
HCC (V28)
No CMS-HCC V28 mapping
RAF
—
Billable
Yes
Payment year
2026

HCC Category Mapping

V24HCC 21, Protein-Calorie Malnutrition
0.455
ESRDHCC 21, Protein-Calorie Malnutrition
0.068

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 E43 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E43

For E43 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 E43 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E43 is the ICD-10-CM diagnosis code for unspecified severe protein-calorie malnutrition. Severe malnutrition due to inadequate protein and calories when the specific type (kwashiorkor vs. marasmus) cannot be determined. E43 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering malnutrition (e40-e46).

Under the older CMS-HCC V24 model, E43 maps to Protein-Calorie Malnutrition (HCC 21) with a community, non-dual, aged base RAF weight of 0.455. 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.

Unspecified severe protein-calorie malnutrition, severe PCM without specification of marasmus vs kwashiorkor. Often used in hospitalized older adults with significant unintentional weight loss. Because E43 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 E43 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •Unspecified severe protein-calorie malnutrition, severe PCM without specification of marasmus vs kwashiorkor. Often used in hospitalized older adults with significant unintentional weight loss.
  • •Severe malnutrition requires documented clinical criteria, ASPEN/AND criteria, albumin, prealbumin, weight loss percentage, and muscle/fat wasting assessment. A bare weight-loss note is not sufficient.
  • •E43 does not map to a V28 payment HCC; protein-calorie malnutrition codes were dropped from the CMS-HCC model in V28. Accurate PCM documentation still matters for clinical and quality purposes, but it no longer captures a risk-adjustment coefficient.

Clinical Significance

Unspecified severe protein-calorie malnutrition indicates that a patient has documented severe malnutrition but the clinical picture does not clearly distinguish between kwashiorkor and marasmus, or the provider has not specified the type. This still represents a life-threatening nutritional state requiring urgent medical intervention and careful refeeding to avoid refeeding syndrome.

Documentation Requirements

  • ✓Documentation should include evidence of severe malnutrition such as body mass index below 16, severe muscle wasting, laboratory markers (albumin below 2.5 g/dL, prealbumin below 5 mg/dL), and functional impairment.
  • ✓The provider should attempt to specify whether edema is present (suggesting kwashiorkor) or absent (suggesting marasmus) for more specific coding.
  • ✓Underlying cause and treatment plan must be documented.

Commonly Confused Codes

  • •E40 (Kwashiorkor), E41 (Nutritional marasmus), and E42 (Marasmic kwashiorkor) are preferred when the type can be determined.
  • •E44.0 (Moderate protein-calorie malnutrition) and E44.1 (Mild protein-calorie malnutrition) indicate less severe forms.
  • •E46 (Unspecified protein-calorie malnutrition) does not specify severity.
  • •Query the provider to determine if E40-E42 can be assigned instead.

Code Hierarchy

└E43Unspecified severe protein-calorie malnutrition
└E43Unspecified severe protein-calorie malnutrition

Because E43 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.

More on E43

Related condition guides

Referenced in blog posts

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