Is K21.0 a billable ICD-10-CM code?

No. K21.0 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does K21.0 sit in the tabular list?

Diseases of the digestive system (K00-K95), in the block Diseases of esophagus, stomach and duodenum (K20-K31).

What cannot be coded together with K21.0?

K21.0 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above K21.0 (K21) and apply to it just the same.

K21.0

K21.0 — Gastro-esophageal reflux disease with esophagitis

Non-billable headerICD-10-CM

K21.0 is a non-billable header ICD-10-CM code for gastro-esophageal reflux disease with esophagitis. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 inherited from the categories above K21.0

These are not written on K21.0, but they bind it: a note on a category applies to every code beneath it. Billing K21.0 with anything listed here is a denial.

Written on K21 — Gastro-esophageal reflux disease

newborn esophageal reflux (P78.83)

Other codes that can never be billed with K21.0

These codes carry an Excludes1 note pointing at K21.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading K21.0 alone.

K20Esophagitis

Risk adjustment

K21.0 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

The condition this code belongs to

Every code for the condition on one page, which one applies when, and the mistake coders make with it.

GERD (gastro-oesophageal reflux disease) ICD-10 codes

Code history

K21.0 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead K21.0

2 child codes. Green means billable.

Related codes at this level

Codes that share K21. If K21.0 is not quite right, the correct code is usually one of these.

K21.9Gastro-esophageal reflux disease without esophagitis

Questions about K21.0

Is K21.0 a billable ICD-10-CM code?: No. K21.0 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does K21.0 sit in the tabular list?: Diseases of the digestive system (K00-K95), in the block Diseases of esophagus, stomach and duodenum (K20-K31).
What cannot be coded together with K21.0?: K21.0 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above K21.0 (K21) and apply to it just the same.