2026 ICD-10-CM Diagnosis Code E55.9Vitamin D deficiency, unspecified

ICD-10-CM Codes›E00–E89›E50-E64›E55

ICD-10-CM E55.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E55.9 is a billable ICD-10-CM diagnosis code for vitamin D 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nutritional deficiencies.

Code Identity

ICD-10-CM Code
E55.9
Billable Status
Yes — Valid for Submission
Code Describes
Vitamin D deficiency, unspecified
Short Description
Vitamin D deficiency, unspecified
Same as the full description in the CMS dataset.
Parent Code
E55
Vitamin D deficiency

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE50-E64Other nutritional deficiencies
CategoryE55Vitamin D deficiency
This CodeE55.9Vitamin D deficiency, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic disease-related malnutrition
  • Deficiency of vitamin D2
  • Deficiency of vitamin D3
  • Disorder of vitamin D
  • Disorder of vitamin D2
  • Disorder of vitamin D3
  • Hyperparathyroidism due to vitamin D deficiency
  • Inadequate intake of vitamin D and/or vitamin D derivative
  • Secondary hyperparathyroidism
  • Vitamin D below reference range
  • Vitamin D deficiency
  • Vitamin D deficiency due to chronic kidney disease

Tabular List NotesGuidance

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

Inclusion Terms

  • Avitaminosis D

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)
      • D
    • Calciferol(vitamin D) deficiency
    • Deficiency, deficient
      • calciferol
    • Deficiency, deficient
      • ergosterol
    • Deficiency, deficient
      • vitamin (multiple) NOS
        • D
    • Ergosterol deficiency(vitamin D)

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Vitamin D Deficiency

    a nutritional condition produced by a deficiency of vitamin d in the diet, insufficient production of vitamin d in the skin, inadequate absorption of vitamin d from the diet, or abnormal conversion of vitamin d to its bioactive metabolites. it is manifested clinically as rickets in children and osteomalacia in adults. (from cecil textbook of medicine, 19th ed, p1406)

  • Nutritional Vitamin D Deficiency Rickets

    nutritional rickets due to dietary deficiency of vitamin d.

  • Vitamin D Deficiency

    abnormally low level of 25-hydroxyvitamin d in the blood.

  • Secondary Hyperparathyroidism

    overproduction of parathyroid hormone in response to influence external to the parathyroid glands.

Patient EducationClinical

Vitamin D Deficiency

Vitamin D deficiency means that your body is not getting enough vitamin D to stay healthy.

The full article covers:

  • What is vitamin D deficiency?
  • Why do I need vitamin D and how do I get it?
  • How much vitamin D do I need?
  • What causes vitamin D deficiency?
  • Who is at risk of vitamin D deficiency?
  • What problems does vitamin D deficiency cause?
  • How can I get more vitamin D?
  • Can too much vitamin D be harmful?

Read the full article at MedlinePlus

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

Convert E55.9 to ICD-9-CMHistory

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

ICD-9-CM
268.9 Vitamin D deficiency NOS
Exact Match The mapping is direct, with no qualifiers.

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 E55.9Overview

Is E55.9 (Vitamin D deficiency) a billable code?

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

What MS-DRG does E55.9 group to?

When vitamin D 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 E55.9?

Under the General Equivalence Mappings, vitamin D deficiency, unspecified converts to ICD-9-CM 268.9 (vitamin D deficiency NOS). The mapping is a direct match.

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.