2026 ICD-10-CM Diagnosis Code R12Heartburn

ICD-10-CM Codes›R00–R99›R10-R19›R12

ICD-10-CM R12
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R12 is a billable ICD-10-CM diagnosis code for heartburn. 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. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abdominal pain and other digestive/abdomen signs and symptoms.

Code Identity

ICD-10-CM Code
R12
Billable Status
Yes — Valid for Submission
Code Describes
Heartburn
Chapter
R10-R19
Symptoms and signs involving the digestive system and abdomen

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR10-R19Symptoms and signs involving the digestive system and abdomen
CategoryR12Heartburn
This CodeR12Heartburn

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Burning pain
  • Digestive system reflux
  • Esophageal reflux finding
  • Finding of esophageal function
  • Functional heartburn
  • Heartburn
  • Pain in esophagus
  • Waterbrash

Tabular List NotesGuidance

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

Type 1 Excludes

  • dyspepsia NOS R10.13
  • functional dyspepsia K30

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.

    • Brash(water)
    • Heartburn
    • Pyrosis
    • Waterbrash

Clinical ClassificationClinical

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

CCSR SYM006
Abdominal pain and other digestive/abdomen signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Heartburn

    substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus.

  • Have Shooting or Burning Pain in Fingers or Hands Question|Did you have shooting or burning pain in your fingers or hands|Have Shooting or Burning Pain in Fingers or Hands

    a question about whether an individual has or had shooting or burning pain in their fingers or hands.

  • Have Shooting or Burning Pain in Toes or Feet Question|Did you have shooting or burning pain in your toes or feet|Have Shooting or Burning Pain in Toes or Feet

    a question about whether an individual has or had shooting or burning pain in their toes or feet.

  • Burning Chest Pain|Burning Pain

    the sensation of chest pain described as an intense discomfort, similar to that experience as a result of a thermal burn, distinct from sharp, stabbing or aching, often related to nerves; sometimes used to describe gastric or esophageal pain.

  • Burning Pain

    a sensation of intensely hot or searing discomfort.

  • Have Shooting or Burning Pain in Fingers or Hands|Did you have shooting or burning pain in your fingers or hands

    a question about whether an individual has or had shooting or burning pain in their fingers or hands.

  • Have Shooting or Burning Pain in Toes or Feet|Did you have shooting or burning pain in your toes or feet

    a question about whether an individual has or had shooting or burning pain in their toes or feet.

  • MNSI - Burning Pain Legs/Feet|MNSI1-Ever Have Burning Pain Legs/Feet|MNSI1-Ever Have Burning Pain Legs/Feet|MNSI102

    michigan neuropathy screening instrument (mnsi) history; do you ever have any burning pain in your legs and/or feet?

  • SF-MPQ-2 - Hot-burning Pain|SFMP2-Hot-burning Pain|SFMP2-Hot-burning Pain|SFMP207

    short-form mcgill pain questionnaire-2 (short form mpq) hot-burning pain.

Patient EducationClinical

Heartburn

Heartburn is a painful burning feeling in your chest or throat. It happens when stomach acid backs up into your esophagus, the tube that carries food from your mouth to your stomach.

Read the full article at MedlinePlus

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

Convert R12 to ICD-9-CMHistory

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

ICD-9-CM
787.1 Heartburn
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 R12Overview

Is R12 (Heartburn) a billable code?

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

What MS-DRG does R12 group to?

When heartburn 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.

Can R12 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the heartburn is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R12?

Under the General Equivalence Mappings, heartburn converts to ICD-9-CM 787.1 (heartburn). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.