2027 ICD-10-CM Diagnosis Code K21.01Gastro-esophageal reflux disease with esophagitis, with bleeding
ICD-10-CM Codes›K00–K95›K20-K31›K21
- Billable — Valid for Submission
- MCC — Major Complication or Comorbidity
- Chronic Condition
K21.01 is a billable ICD-10-CM diagnosis code for gastro-esophageal reflux disease with esophagitis, with bleeding. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 368 through 370. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 38 closely related codes. Coders also document this condition as hemorrhage of lower esophagus due to erosive gastro-esophageal reflux disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Esophageal disorders and Gastrointestinal hemorrhage.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Hemorrhage of lower esophagus due to erosive gastro-esophageal reflux disease
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to K21.01: its own notes plus those printed at K21, block K20-K31, and Chapter 11. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- hiatus hernia (K44.-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name K21.01, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming K21.01: they are not reported together with it, unless the two conditions are unrelated.
Code Also 2
These codes say K21.01 may also be needed to fully describe the condition. The note gives no sequencing direction.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Allergy, allergic (reaction) (to) T78.40
milk protein See Also: Allergy, food; Z91.0110
gastroesophageal reflux See Also: Reaction, adverse, food; K21.9
Disease, diseased See Also: Syndrome;
Esophagitis (acute) (alkaline) (chemical) (chronic) (infectional) (necrotic) (peptic) (postoperative) (without bleeding) K20.90
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Gastroesophageal Reflux
retrograde flow of gastric juice (gastric acid) and/or duodenal contents (bile acids; pancreatic juice) into the distal esophagus, commonly due to incompetence of the lower esophageal sphincter.
Patient EducationClinical
Esophagus Disorders
Esophagus disorders are problems with how your esophagus works. The esophagus is the tube that carries food from your mouth to your stomach. You usually don't notice it unless you swallow something too big, hot, or cold. You might also notice it if something is wrong.
The full article covers:
- What are esophagus disorders?
- What causes esophagus disorders?
- What are common esophagus disorders?
- What are symptoms of esophagus disorders?
- How are esophagus disorders diagnosed?
- How are esophagus disorders treated?
- Can esophagus disorders be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code History & ChangesHistory
Replacement K21.01 replaces the following previously assigned code(s):
- K21.0 - Gastro-esophageal reflux disease with esophagitis
Questions About K21.01Overview
What is the ICD-10 code for gastro-esophageal reflux disease with esophagitis, with bleeding?
The ICD-10-CM code for gastro-esophageal reflux disease with esophagitis, with bleeding is K21.01 (sometimes written as K2101). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is K21.01 (Gastro-esophageal reflux disease with esophagitis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report gastro-esophageal reflux disease with esophagitis, with bleeding on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does K21.01 group to?
When gastro-esophageal reflux disease with esophagitis, with bleeding is the principal diagnosis on an inpatient stay, it groups to MS-DRG 369, 370, 368, with relative weights from 0.6741 to 1.6434 depending on complications. Higher weights mean higher Medicare reimbursement.
Is K21.01 a CC or MCC?
CMS lists K21.01 as an MCC (major complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 38 closely related codes in its exclusion list.
Can K21.01 be reported with P78.83?
Not as a rule. The Excludes1 note at K21, which applies to K21.01, lists "newborn esophageal reflux (P78.83)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
