2027 ICD-10-CM Diagnosis Code K81.1Chronic cholecystitis

ICD-10-CM Codes›K00–K95›K80-K87›K81

ICD-10-CM K81.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

K81.1 is a billable ICD-10-CM diagnosis code for chronic cholecystitis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 444 through 446. Coders also document this condition as cholecystitis glandularis proliferans. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Biliary tract disease.

Code Identity

ICD-10-CM Code
K81.1
Billable Status
Yes — Valid for Submission
Code Describes
Chronic cholecystitis
Short Description
Chronic cholecystitis
Same as the full description in the CMS dataset.
Parent Code
K81
Cholecystitis

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK80-K87Disorders of gallbladder, biliary tract and pancreas
CategoryK81Cholecystitis
This CodeK81.1Chronic cholecystitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cholecystitis glandularis proliferans
  • Cholecystitis without calculus
  • Chronic cholecystitis
  • Chronic cholecystitis without calculus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to K81.1: its own notes plus those printed at K81 and Chapter 11. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From K81 Cholecystitis applies to 4 codes
  • cholecystitis with cholelithiasis (K80.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 11 (K00-K95) Diseases of the digestive system applies to 863 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From K81 Cholecystitis applies to 4 codes
  • code if applicable for associated gangrene of gallbladder (K82.A1), or perforation of gallbladder (K82.A2)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name K81.1, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming K81.1: they are not reported together with it, unless the two conditions are unrelated.

  • K82.4 Cholesterolosis of gallbladder
    cholesterolosis of gallbladder with cholecystitis (K81.-) names K81.-, which includes this code

Excludes2 2

These codes carry an Excludes2 note naming K81.1: its condition is not part of those codes, and both may be reported when the patient has both.

  • K83 Other diseases of biliary tract
    conditions involving the gallbladder (K81-K82) names K81-K82, which includes this code
  • K83 Other diseases of biliary tract
    conditions involving the cystic duct (K81-K82) names K81-K82, which includes this code

Code First 1

These codes say to code first a condition named in the note, and K81.1 is one of the conditions named.

  • K82.A Disorders of gallbladder in diseases classified elsewhere
    the type of cholecystitis (K81.-), or cholelithiasis with cholecystitis (K80.00-K80.19, K80.40-K80.47, K80.60-K80.67) names K81.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR DIG017
Biliary tract disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Chronic Cholecystitis

    cholecystitis that is persistent and long-standing.

  • Cholecystitis

    inflammation of the gallbladder; generally caused by impairment of bile flow, gallstones in the biliary tract, infections, or other diseases.

Patient EducationClinical

Gallbladder Diseases

Your gallbladder is a pear-shaped organ under your liver. It stores bile, a fluid made by your liver to digest fat. As your stomach and intestines digest food, your gallbladder releases bile through a tube called the common bile duct. The duct connects your gallbladder and liver to your small intestine.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert K81.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
575.11 Chronic cholecystitis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About K81.1Overview

What is the ICD-10 code for chronic cholecystitis?

The ICD-10-CM code for chronic cholecystitis is K81.1 (sometimes written as K811). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is K81.1 (Cholecystitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic cholecystitis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does K81.1 group to?

When chronic cholecystitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 444, 445, 446, with relative weights from 0.8121 to 1.6662 depending on complications. Higher weights mean higher Medicare reimbursement.

Can K81.1 be reported with a code from K80?

Not as a rule. The Excludes1 note at K81, which applies to K81.1, lists "cholecystitis with cholelithiasis (K80.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does K81.1 need an additional code?

When the condition applies, yes. The Use Additional Code note at K81, which applies to K81.1, reads: code if applicable for associated gangrene of gallbladder (K82.A1), or perforation of gallbladder (K82.A2). The additional code is reported after K81.1.