2026 ICD-10-CM Diagnosis Code K90.9Intestinal malabsorption, unspecified

ICD-10-CM Codes›K00–K95›K90-K95›K90

ICD-10-CM K90.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K90.9 is a billable ICD-10-CM diagnosis code for intestinal malabsorption, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified gastrointestinal disorders.

Code Identity

ICD-10-CM Code
K90.9
Billable Status
Yes — Valid for Submission
Code Describes
Intestinal malabsorption, unspecified
Short Description
Intestinal malabsorption, unspecified
Same as the full description in the CMS dataset.
Parent Code
K90
Intestinal malabsorption

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK90-K95Other diseases of the digestive system
CategoryK90Intestinal malabsorption
This CodeK90.9Intestinal malabsorption, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal intestinal absorption
  • Chronic steatorrhea
  • Deficiency of coagulation factor due to vitamin K deficiency
  • Disorder of gastrointestinal tract co-occurrent with human immunodeficiency virus infection
  • Fatty stool
  • Folate deficiency anemia due to malabsorption
  • Gastrointestinal malabsorption syndrome co-occurrent with human immunodeficiency virus infection
  • Gastrointestinal sequelae of disorders
  • Gastrointestinal test finding
  • Hyperparathyroidism due to intestinal malabsorption
  • Intestinal malabsorption
  • Intestinal malabsorption due to bile acid synthesis defect
  • Intolerance to monosodium glutamate
  • Intolerance to substance
  • Malabsorption caused by infective agent
  • Malabsorption syndrome
  • Malabsorption syndrome due to acquired intolerance to fructose
  • Malabsorption syndrome due to intolerance to lactose
  • Megaloblastic anemia due to impaired absorption of folate
  • Osteoporosis due to malabsorption
  • Post-infective malabsorption
  • Primary malabsorption of infancy
  • Vitamin K deficiency coagulation disorder due to malabsorption

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.

    • Disturbance(s)
      • absorption
    • Disturbance(s)
      • assimilation, food
    • Malabsorption
    • Malabsorption
      • intestinal
    • Malabsorption
      • syndrome
    • Malassimilation
    • Steatorrhea(chronic)
    • Steatorrhea(chronic)
      • idiopathic (adult) (infantile)
    • Syndrome
      • malabsorption

Clinical ClassificationClinical

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

CCSR DIG025
Other specified and unspecified gastrointestinal disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Intolerance to Substance

    an individual has an inability to process a substance without adverse effects.

Patient EducationClinical

Malabsorption Syndromes

Your small intestine does most of the digesting of the foods you eat. If you have a malabsorption syndrome, your small intestine cannot absorb nutrients from foods.

Read the full article at MedlinePlus

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

Convert K90.9 to ICD-9-CMHistory

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

ICD-9-CM
579.9 Intest malabsorption 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 K90.9Overview

Is K90.9 (Intestinal malabsorption) a billable code?

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

What MS-DRG does K90.9 group to?

When intestinal malabsorption, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K90.9?

Under the General Equivalence Mappings, intestinal malabsorption, unspecified converts to ICD-9-CM 579.9 (intest malabsorption 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.