2026 ICD-10-CM Diagnosis Code E46Unspecified protein-calorie malnutrition

ICD-10-CM Codes›E00–E89›E40-E46›E46

ICD-10-CM E46
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E46 is a billable ICD-10-CM diagnosis code for unspecified protein-calorie malnutrition. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 640 through 641, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 9 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Malnutrition.

E46 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 21 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 21, ESRD (V21) category 21, and ESRD (V24) category 21 for payment year 2026.

Code Identity

ICD-10-CM Code
E46
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified protein-calorie malnutrition
Short Description
Unspecified protein-calorie malnutrition
Same as the full description in the CMS dataset.
Chapter
E40-E46
Malnutrition

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE40-E46Malnutrition
CategoryE46Unspecified protein-calorie malnutrition
This CodeE46Unspecified protein-calorie malnutrition

Medicare Risk Adjustment (HCC)Billing

E46 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 21
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 21 · ESRD (V21): HCC 21 · ESRD (V24): HCC 21
ESRD V21 weights: 0.055 dialysis, 0.252–0.593 functioning graft · ESRD V24 weights: 0.068 dialysis, 0.326–0.963 functioning graft
Part D (RxHCC)
Not mapped
E46 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute disease or injury-related malnutrition
  • Acute malnutrition in adolescence
  • Acute malnutrition in childhood
  • Acute malnutrition in infancy
  • Cataract due to undernutrition
  • Cataract in systemic disorders
  • Child neglect
  • Chronic disease-related malnutrition
  • Coma due to malnutrition-related diabetes mellitus
  • Deficiency of macronutrients
  • Diabetes mellitus associated with pancreatic disease
  • Diabetic ketoacidosis
  • Disorder due to malnutrition related diabetes mellitus
  • Disorder of eye due to malnutrition related diabetes mellitus
  • Disorder of nervous system due to malnutrition related diabetes mellitus
  • Disorder of vision due to secondary diabetes mellitus
  • Fibrocalculous pancreatic diabetes
  • Generalized redundant skin due to malnutrition
  • Gingival disease due to malnutrition
  • Hair changes due to malnutrition
  • Hypertrichosis in malnutrition
  • Hypoalbuminemia
  • Hypoalbuminemia due to protein calorie malnutrition
  • Hypoproteinemia
  • Inadequate intake of energy
  • Inadequate intake of protein and/or protein derivative
  • Ketoacidosis due to secondary diabetes mellitus
  • Malnutrition
  • Malnutrition due to child maltreatment
  • Malnutrition related diabetes mellitus
  • Malnutrition-dehydration cataract
  • Malnutrition-related diabetes mellitus - fibrocalculous
  • Malnutrition-related diabetes mellitus with ketoacidosis
  • Nutritional hair color change
  • Nutritional maltreatment of child
  • Nutritional myopathy
  • Nutritionally compromised
  • Peripheral circulatory disorder due to malnutrition-related diabetes mellitus
  • Peripheral vascular disease due to secondary diabetes mellitus
  • Peripheral vascular disorder due to diabetes mellitus
  • Pre-existing diabetes mellitus in pregnancy
  • Pre-existing malnutrition-related diabetes mellitus
  • Pre-existing malnutrition-related diabetes mellitus in pregnancy
  • Protein deficiency disease
  • Protein deficiency myopathy
  • Protein-deficient diabetes mellitus
  • Redundant skin
  • Skin changes due to malnutrition
  • Starvation-related malnutrition
  • Undernutrition

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Malnutrition NOS
  • Protein-calorie imbalance NOS

Type 1 Excludes

  • nutritional deficiency NOS E63.9

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END008
Malnutrition
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Hypoalbuminemia

    a condition in which albumin level in blood (serum albumin) is below the normal range. hypoalbuminemia may be due to decreased hepatic albumin synthesis, increased albumin catabolism, altered albumin distribution, or albumin loss through the urine (albuminuria).

  • Child Nutrition Disorders

    disorders caused by nutritional imbalance, either overnutrition or undernutrition, occurring in children ages 2 to 12 years.

  • Fetal Nutrition Disorders

    disorders caused by nutritional imbalance, either overnutrition or undernutrition, in the fetus in utero.

  • Infant Nutrition Disorders

    disorders caused by nutritional imbalance, either overnutrition or undernutrition, occurring in infants ages 1 month to 24 months.

  • Malnutrition

    an imbalanced nutritional status resulting from insufficient intake of nutrients to meet normal physiological requirement.

  • Protein-Energy Malnutrition

    the lack of sufficient energy or protein to meet the body's metabolic demands, as a result of either an inadequate dietary intake of protein, intake of poor quality dietary protein, increased demands due to disease, or increased nutrient losses.

  • Severe Acute Malnutrition

    acute form of malnutrition which usually affects children, characterized by a very low weight for height (below -3z scores of the median world health organization standards), visible severe wasting, or occurrence of nutritional edema. it can be a direct or indirect cause of fatality in children suffering from diarrhea and pneumonia. do not confuse with starvation, a condition in which the body is not getting enough food, usually for extended periods of time.

  • Diabetic Ketoacidosis

    a life-threatening complication of diabetes mellitus, primarily of type 1 diabetes mellitus with severe insulin deficiency and extreme hyperglycemia. it is characterized by ketosis; dehydration; and depressed consciousness leading to coma.

  • Hypoproteinemia

    a condition in which total serum protein level is below the normal range. hypoproteinemia can be caused by protein malabsorption in the gastrointestinal tract, edema, or proteinuria.

  • Protein-Losing Enteropathies

    pathological conditions in the intestines that are characterized by the gastrointestinal loss of serum proteins, including serum albumin; immunoglobulins; and at times lymphocytes. severe condition can result in hypogammaglobulinemia or lymphopenia. protein-losing enteropathies are associated with a number of diseases including intestinal lymphangiectasis; whipple's disease; and neoplasms of the small intestine.

  • Fetus

    the unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. in humans, the unborn young from the end of the eighth week after conception until birth, as distinguished from the earlier embryo, mammalian.

  • Grade 1 Hypoalbuminemia, CTCAE|Grade 1 Hypoalbuminemia

  • Grade 2 Hypoalbuminemia, CTCAE|Grade 2 Hypoalbuminemia

    <3 - 2 g/dl; <30 - 20 g/l

  • APTX wt Allele|AOA|AOA1|AXA1|Aprataxin wt Allele|Ataxia 1, Early Onset With Hypoalbuminemia Gene|EAOH|EOAHA|FHA-HIT

    human aptx wild-type allele is located in the vicinity of 9p21.1 and is approximately 139 kb in length. this allele, which encodes aprataxin protein, is involved in dna repair. mutation of the gene is associated with ataxia-ocular apraxia type 1.

  • Ataxia-Oculomotor Apraxia Type 1|AOA1|Ataxia, Early-Onset, with Oculomotor Apraxia and Hypoalbuminemia|EAOH

    an autosomal recessive cerebellar ataxia caused by mutation(s) in the aptx gene, encoding aprataxin. it is characterized by peripheral axonal neuropathy, oculomotor apraxia, and hypoalbuminemia.

  • Grade 1 Hypoalbuminemia, CTCAE|Grade 1 Hypoalbuminemia

  • Grade 2 Hypoalbuminemia, CTCAE|Grade 2 Hypoalbuminemia

    <3-2 g/dl; <30-20 g/l

  • Grade 3 Hypoalbuminemia, CTCAE|Grade 3 Hypoalbuminemia

    <2 g/dl; <20 g/l

  • Grade 4 Hypoalbuminemia, CTCAE|Grade 4 Hypoalbuminemia

    life-threatening consequences; urgent intervention indicated

  • Grade 5 Hypoalbuminemia, CTCAE|Grade 5 Hypoalbuminemia

    death

  • Hypoalbuminemia

    concentration of serum albumin below normal limits for the age related normal range.

  • Hypoalbuminemia, CTCAE|Hypoalbuminemia|Hypoalbuminemia

    a disorder characterized by laboratory test results that indicate a low concentration of albumin in the blood.

  • Hypoproteinemia

    a laboratory test result indicating abnormally low levels of total protein in the serum.

Patient EducationClinical

Malnutrition

Malnutrition means that your body isn't getting enough calories or the right balance of nutrients to stay healthy. This can happen if you don't get enough protein, carbohydrates, and fats, eat too much unhealthy food, or don't get the vitamins and minerals your body needs.

The full article covers:

  • What is malnutrition?
  • What are the types of malnutrition?
  • What causes malnutrition?
  • Who is at risk for developing malnutrition?
  • What are the symptoms of malnutrition?
  • How is malnutrition diagnosed?
  • What are the treatments for malnutrition?
  • Can malnutrition be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E46 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
263.8 Protein-cal malnutr NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
263.9 Protein-cal malnutr NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E46Overview

What is the ICD-10 code for unspecified protein-calorie malnutrition?

The ICD-10-CM code for unspecified protein-calorie malnutrition is E46. It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is E46 (Unspecified protein-calorie malnutrition) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified protein-calorie malnutrition on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E46 group to?

When unspecified protein-calorie malnutrition is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, 791, 793, with relative weights from 0.7782 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is E46 a CC or MCC?

CMS lists E46 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 9 closely related codes in its exclusion list.

What is the ICD-9 equivalent of E46?

Under the General Equivalence Mappings, unspecified protein-calorie malnutrition converts to ICD-9-CM 263.8 (protein-cal malnutr NEC) and 263.9 (protein-cal malnutr NOS). The mapping is approximate, so confirm the match fits the documentation.

Does E46 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. E46 mapped to HCC 21 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 21 (Protein-Calorie Malnutrition), ESRD (V21) category 21 (Protein-Calorie Malnutrition), and ESRD (V24) category 21 (Protein-Calorie Malnutrition).