What is the ICD-10 code for malnutrition?

The ICD-10-CM code for malnutrition is E46 when documented without further specification. More specific documentation changes the code — see the scenario table.

Yes — E46 is a billable ICD-10-CM code, but payers expect the most specific code the documentation supports.

ICD-10 Code for malnutrition

The ICD-10-CM code for malnutrition is E46 when documented without further specification. HCC Malnutrition (protein-calorie malnutrition) codes to E46 when documented without a specified degree. E46 is the unspecified default; a documented severity supports a more specific malnutrition code, and a general nutritional deficiency NOS is classified elsewhere.

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Symptom code vs. confirmed diagnosis

E46 is a confirmed-diagnosis code requiring provider documentation of protein-calorie malnutrition; it is not assigned from weight or albumin values alone. Per the Excludes1, unqualified nutritional deficiency NOS is coded to E63.9, not E46, and a documented degree moves coding to a more specific malnutrition code.

Which Code Should You Use?

E46 ✓ Billable — Unspecified protein-calorie malnutrition

Protein-calorie malnutrition documented without a specified degree.

E63.9 ✓ Billable — Nutritional deficiency, unspecified

Nutritional deficiency, unspecified (Excludes1) - when the record documents a nutritional deficiency NOS rather than malnutrition.

What to Document

That the provider documents malnutrition (or protein-calorie malnutrition) as a diagnosis rather than an isolated lab or weight finding.
The degree of malnutrition (mild, moderate, or severe) when stated, which supports a more specific code than E46.
Any underlying cause or associated condition the provider links.

Common Documentation Pitfalls

Per the Excludes1, do not use E46 for a nutritional deficiency NOS statement - that is E63.9.
E46 is the unspecified-degree code - when severity is documented, a more specific malnutrition code applies.
Do not assign malnutrition from low albumin or BMI alone - it requires a provider diagnosis.

Instructional Notes for E46

Excludes1

Not coded here. These conditions should NOT be coded together with E46.

nutritional deficiency NOS (E63.9)

Also Known As

Official ICD-10-CM Alphabetic Index terms that point to E46:

Malnutrition
Calorie deficiency or malnutrition
Malnutrition › protein
Cataract (cortical) (immature) (incipient) › malnutrition-dehydration
Deficiency, deficient › protein
Malnutrition › protein › calorie
Malnutrition › protein › energy
Cataract (cortical) (immature) (incipient) › in (due to) › malnutrition-dehydration

Coding Notes

The Alphabetic Index maps Malnutrition and protein-calorie malnutrition to E46 when the degree is unspecified. Its Excludes1 directs nutritional deficiency NOS to E63.9.