MCMCB Pro
K35

K35Acute appendicitis

Non-billable headerICD-10-CM

K35 is a non-billable header ICD-10-CM code for acute appendicitis. It cannot be billed on its own: choose one of the more specific child codes below.

Other codes that can never be billed with K35

These codes carry an Excludes1 note pointing at K35. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading K35 alone.

  • K37Unspecified appendicitis
  • K65Peritonitis

Risk adjustment

K35 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.

Code to one of these instead K35

3 child codes. Green means billable.

Questions about K35

Is K35 a billable ICD-10-CM code?
No. K35 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does K35 sit in the tabular list?
Diseases of the digestive system (K00-K95), in the block Diseases of appendix (K35-K38).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.