2026 ICD-10-CM Diagnosis Code K90.49Malabsorption due to intolerance, not elsewhere classified

ICD-10-CM CodesK00–K95K90-K95K90

ICD-10-CM K90.49
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K90.49 is a billable ICD-10-CM diagnosis code for malabsorption due to intolerance, not elsewhere classified. 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
K90.49
Billable Status
Yes — Valid for Submission
Code Describes
Malabsorption due to intolerance, not elsewhere classified
Short Description
Malabsorption due to intolerance, not elsewhere classified
Same as the full description in the CMS dataset.
Parent Code
Other malabsorption due to intolerance

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK90-K95Other diseases of the digestive system
CategoryK90Intestinal malabsorption
This CodeK90.49Malabsorption due to intolerance, not elsewhere classified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic diarrhea of infants AND/OR young children
  • Complement hyperactivation, angiopathic thrombosis, protein losing enteropathy syndrome
  • Congenital chronic diarrhea with protein-losing enteropathy
  • Decay accelerating factor deficiency
  • D-Xylose intolerance
  • D-Xylose tolerance - finding
  • Exudative enteropathy
  • Gastrointestinal tolerance finding
  • Impaired intestinal fat absorption
  • Impaired intestinal protein absorption
  • Intestinal malabsorption
  • Intestinal malabsorption of carbohydrate
  • Intestinal malabsorption of fat
  • Intestinal malabsorption of protein
  • Intolerance to cow milk
  • Intolerance to food
  • Intolerance to infant formula
  • Intolerance to milk
  • Intolerance to monosodium glutamate
  • Malabsorption due to intolerance to carbohydrate
  • Malabsorption due to intolerance to fat
  • Malabsorption due to intolerance to protein
  • Malabsorption due to intolerance to soy protein
  • Monosodium glutamate symptom complex
  • Protein malabsorption
  • Protein-losing enteropathy
  • Syndrome of carbohydrate intolerance
  • Wheat intolerance

Tabular List NotesGuidance

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

Inclusion Terms

  • Malabsorption due to intolerance to carbohydrate
  • Malabsorption due to intolerance to fat
  • Malabsorption due to intolerance to protein
  • Malabsorption due to intolerance to starch

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.

    • Absorption
      • carbohydrate, disturbance
    • Absorption
      • fat, disturbance
    • Absorption
      • protein, disturbance
    • Absorption
      • starch, disturbance
    • Decrease(d)
      • tolerance
        • fat
    • Disturbance(s)
      • absorption
        • carbohydrate
    • Disturbance(s)
      • absorption
        • fat
    • Disturbance(s)
      • absorption
        • protein
    • Disturbance(s)
      • absorption
        • starch
    • Enteropathy
      • protein-losing
    • Intolerance
      • carbohydrate
    • Intolerance
      • fat NEC
    • Intolerance
      • food
    • Intolerance
      • milk NEC
    • Intolerance
      • protein
    • Intolerance
      • starch NEC
    • Malabsorption
      • carbohydrate
    • Malabsorption
      • fat
    • Malabsorption
      • protein
    • Malabsorption
      • starch
    • Sprue(tropical)
      • idiopathic

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

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 K90.49 to ICD-9-CMHistory

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

ICD-9-CM
579.8 Intest malabsorption NEC
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement K90.49 replaces the following previously assigned code(s):

  • K90.4 - Malabsorption due to intolerance, not elsewhere classified
  • K90.4 - Other malabsorption due to intolerance
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K90.49Overview

Is K90.49 (Other malabsorption due to intolerance) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malabsorption due to intolerance, not elsewhere classified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K90.49 group to?

When malabsorption due to intolerance, not elsewhere classified 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 K90.49?

Under the General Equivalence Mappings, malabsorption due to intolerance, not elsewhere classified converts to ICD-9-CM 579.8 (intest malabsorption NEC). 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.