Is K65 a billable ICD-10-CM code?

No. K65 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does K65 sit in the tabular list?

Diseases of the digestive system (K00-K95), in the block Diseases of peritoneum and retroperitoneum (K65-K68).

What cannot be coded together with K65?

K65 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

K65

K65 — Peritonitis

Non-billable headerICD-10-CM

K65 is a non-billable header ICD-10-CM code for peritonitis. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

acute appendicitis with generalized peritonitis (K35.2-)
aseptic peritonitis (T81.6)
benign paroxysmal peritonitis (E85.0)
chemical peritonitis (T81.6)
gonococcal peritonitis (A54.85)
neonatal peritonitis (P78.0-P78.1)
pelvic peritonitis, female (N73.3-N73.5)
periodic familial peritonitis (E85.0)
peritonitis due to talc or other foreign substance (T81.6)
peritonitis in chlamydia (A74.81)
peritonitis in diphtheria (A36.89)
peritonitis in syphilis (late) (A52.74)
peritonitis in tuberculosis (A18.31)
peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
peritonitis with or following appendicitis (K35.-)
puerperal peritonitis (O85)
retroperitoneal infections (K68.-)

Use additional code

Add a secondary code to capture the detail described below.

code (B95-B97), to identify infectious agent, if known

Code also

Both codes may be needed to describe the encounter fully. Sequencing depends on the reason for the visit.

if applicable diverticular disease of intestine (K57.-)

Other codes that can never be billed with K65

These codes carry an Excludes1 note pointing at K65. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading K65 alone.

K65.2Spontaneous bacterial peritonitis

Risk adjustment

K65 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 K65

7 child codes. Green means billable.

Questions about K65

Is K65 a billable ICD-10-CM code?: No. K65 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does K65 sit in the tabular list?: Diseases of the digestive system (K00-K95), in the block Diseases of peritoneum and retroperitoneum (K65-K68).
What cannot be coded together with K65?: K65 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.