Reserved for future guideline expansion
K21.9
BookmarkGastro-esophageal reflux disease without esophagitis
Filed alongside this entry 4
under Reflux
Index entries, exactly as the book files them. This says they are listed together — not that any of them is documented in your chart.
Billable FY2027 2026-10-01 → 2027-09-30
How to use this page
Everything the published sources say about one code, on one page.
- Read the Excludes1 block first — it is the one that stops you coding this at all alongside another code.
- Excludes2, Code first, Use additional and Includes follow. A note inherited from a parent category is labelled with the category it came from, so you can see why it applies.
- Official Guidelines sit below. "Guidelines naming this code" cite the code or a range containing it; "Chapter guidance" is the general guidance for its chapter and is the weaker signal.
- Guideline text is quoted verbatim with its section number and page, so you can check it against the published document.
- Risk-model chips show which published CMS models map this code.
What this page does not do
- Guidance is quoted, never paraphrased — a paraphrase of a coding rule is a different rule.
- Medication candidates, where shown, are matched by condition *name* and are offered as candidates for you to judge. They are not "the drugs for this code".
Exclusions10never code together
K00-K95chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes1
K21.9code
Inclusion terms
- Esophageal reflux NOS
Official Guidelines1names this code
ICD-10-CM Official Guidelines for Coding and Reporting, quoted in full. Published by CMS and NCHS; in the public domain.
Index entries leading here7
Alongside this code1same parent — K21
Medications1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.