2026 ICD-10-CM Diagnosis Code E56.9Vitamin deficiency, unspecified

ICD-10-CM Codes›E00–E89›E50-E64›E56

ICD-10-CM E56.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E56.9 is a billable ICD-10-CM diagnosis code for vitamin deficiency, unspecified. 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. Coders also document this condition as acquired ataxia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nutritional deficiencies.

Code Identity

ICD-10-CM Code
E56.9
Billable Status
Yes — Valid for Submission
Code Describes
Vitamin deficiency, unspecified
Short Description
Vitamin deficiency, unspecified
Same as the full description in the CMS dataset.
Parent Code
E56
Other vitamin deficiencies

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE50-E64Other nutritional deficiencies
CategoryE56Other vitamin deficiencies
This CodeE56.9Vitamin deficiency, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired ataxia
  • Acquired ataxia due to vitamin deficiency
  • Encephalopathy due to vitamin deficiency
  • Inadequate vitamin intake
  • Multiple vitamin deficiency disease
  • Vitamin deficiency
  • Vitamin deficiency related neuropathy
  • Vitamin disease

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Avitaminosis(multiple)
    • Deficiency, deficient
      • vitamin (multiple) NOS
    • Encephalopathy(acute)
      • in (due to) (with)
        • lack of vitamin
    • Neuroavitaminosis
    • Polyneuritis, polyneuritic
      • due to lack of vitamin NEC
    • Polyneuropathy(peripheral)
      • in (due to)
        • avitaminosis NEC
    • Polyneuropathy(peripheral)
      • in (due to)
        • lack of vitamin NEC

Clinical ClassificationClinical

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

CCSR END007
Nutritional deficiencies
Default principal diagnosis: inpatient Yes · outpatient Yes

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 E56.9 to ICD-9-CMHistory

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

ICD-9-CM
269.2 Vitamin Deficiency 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 E56.9Overview

Is E56.9 (Other vitamin deficiencies) a billable code?

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

What MS-DRG does E56.9 group to?

When vitamin deficiency, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, with relative weights from 0.7782 to 1.3356 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E56.9?

Under the General Equivalence Mappings, vitamin deficiency, unspecified converts to ICD-9-CM 269.2 (vitamin Deficiency NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.