ICD-10-CM 2027
ICD-10 code for stomach acid
From the official ICD-10-CM alphabetic index entry “Acid › stomach”. Page updated September 29, 2026.
About coding stomach acid
The ICD-10-CM code for stomach acid is K30 (Functional dyspepsia). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on K30.
Don't report K30 together with the conditions in its Excludes1 note: dyspepsia NOS (R10.13), heartburn (R12), nervous dyspepsia (F45.8), neurotic dyspepsia (F45.8) and 1 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC, relative weight 1.2392) and DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC, relative weight 0.7645), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific stomach acid codes (official index)
- psychogenic F45.8 — Other somatoform disorders
Don't confuse with (Excludes1 for K30)
Common questions about stomach acid ICD-10 codes
What is the ICD-10 code for stomach acid?
- K30 — Functional dyspepsia. More specific codes apply when the documentation supports them: F45.8.
What is the ICD-10 code for psychogenic stomach acid?
- F45.8 — Other somatoform disorders.
Is K30 billable?
- Yes. K30 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K30 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K30 as a principal diagnosis.
Is K30 a CC or MCC?
- No. K30 is neither a CC nor an MCC under MS-DRG v44.0.