K21.00 — Gastro-esophageal reflux disease with esophagitis, without bleeding
Is K21.00 billable?
Yes — K21.00 is billable for FY2027. K21.00 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. K21.00 may be submitted for encounters from October 1, 2026 through September 30, 2027.
K21.00 at a glance
| Code | K21.00 |
|---|---|
| Description | Gastro-esophageal reflux disease with esophagitis, without bleeding |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does K21.00 group to?
K21.00 sits in MDC 06 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 391Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCCmedical
- 392Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCCmedical
How is K21.00 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to K21.00. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Esophagitis › due to gastrointestinal reflux disease (acute) (alkaline) (chemical) (chronic) (infectional) (necrotic) (peptic) (postoperative) (without bleeding)
- Esophagitis › reflux (acute) (alkaline) (chemical) (chronic) (infectional) (necrotic) (peptic) (postoperative) (without bleeding)
- Disease, diseased › gastroesophageal reflux › with esophagitis
- Reflux › esophageal › with esophagitis
- Reflux › gastroesophageal › with esophagitis
- Allergy, allergic › milk protein › gastroesophageal reflux › with esophagitis (reaction) (to)
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative › esophagus › due to › gastrointestinal reflux disease
Inclusion terms
Alternative wording in documentation that is classified to K21.00.
- Reflux esophagitis
Excludes1 — never code together — inherited from K21
The conditions below can never be reported together with K21.00 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- newborn esophageal reflux (P78.83)
Excludes2 — not included here — inherited from Chapter 11
The conditions below are not part of K21.00, but a patient may have both at the same time. When documentation supports it, K21.00 and the excluded code may both be reported.
- 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)
Excludes2 — not included here — inherited from K20-K31
The conditions below are not part of K21.00, but a patient may have both at the same time. When documentation supports it, K21.00 and the excluded code may both be reported.
- hiatus hernia (K44.-)
How long has K21.00 existed?
K21.00 first appears in FY2021 (FY2020 is not available, so it may have appeared then).
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.