ICD10BillableValid for clinical use

ICD-10 Code K59.9: Functional intestinal disorder, unspecified

K59.9 is a billable ICD-10 diagnosis code used to classify Functional intestinal disorder, unspecified in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the digestive system (K00-K95).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the digestive system (K00-K95).

When is it used?

  • May be used when a clinician documents functional intestinal disorder, unspecified in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
11Diseases of the digestive system (K00-K95)
block
K55-K64Other diseases of intestines
category
K59Other functional intestinal disorders
currentK59

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

GastroenterologistGeneral Physician

Coverage-related procedures and services

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
K59.9

Common synonyms

Functional intestinal disorder, unspecifiedFunctional intestinal disorder

Frequently asked questions

Code details

CodeK59.9
SystemICD10
Display nameFunctional intestinal disorder, unspecified
ChapterDiseases of the digestive system (K00-K95)
BlockOther diseases of intestines

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
ComplaintComplaintDisease, diseasedDisease, diseasedDisease, diseasedDisease, diseasedDisorder(of)DistressDysfunctionDysfunctionSyndromeUpset

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code K59.9 for Functional intestinal disorder, unspecified | HealthAssure