2027 ICD-10-CM Diagnosis Code K80.66Calculus of gallbladder and bile duct with acute and chronic cholecystitis without obstruction
ICD-10-CM Codes›K00–K95›K80-K87›K80
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
K80.66 is a billable ICD-10-CM diagnosis code for calculus of gallbladder and bile duct with acute and chronic cholecystitis without obstruction. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 10 closely related codes. Coders also document this condition as acute and chronic cholecystitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Biliary tract disease.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute and chronic cholecystitis
- Acute and chronic cholecystitis co-occurrent and due to calculus of gallbladder and bile duct
- Calculus of gallbladder and bile duct with acute and chronic cholecystitis
- Calculus of gallbladder and bile duct with cholecystitis
- Calculus of gallbladder with acute and chronic cholecystitis
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to K80.66: its own notes plus those printed at K80.6, K80, 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.
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.
- 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.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name K80.66, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming K80.66: they are not reported together with it, unless the two conditions are unrelated.
- K81 Cholecystitischolecystitis with cholelithiasis (K80.-) names K80.-, which includes this code
- K82.0 Obstruction of gallbladderobstruction of gallbladder with cholelithiasis (K80.-) names K80.-, which includes this code
- K82.4 Cholesterolosis of gallbladdercholesterolosis of gallbladder with cholelithiasis (K80.-) names K80.-, which includes this code
- K83.1 Obstruction of bile ductobstruction of bile duct with cholelithiasis (K80.-) names K80.-, which includes this code
Code First 1
These codes say to code first a condition named in the note, and K80.66 is one of the conditions named.
- K82.A Disorders of gallbladder in diseases classified elsewhere
Use Additional Code 6
These codes say to use an additional code from the note, and K80.66 is one of the codes named.
- D57.09 Hb-SS disease with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, which includes this code
- D57.218 Sickle-cell/Hb-C disease with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, which includes this code
- D57.418 Sickle-cell thalassemia, unspecified, with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, which includes this code
- D57.438 Sickle-cell thalassemia beta zero with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, which includes this code
- D57.458 Sickle-cell thalassemia beta plus with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, which includes this code
- D57.818 Other sickle-cell disorders with crisis with other specified complicationcholelithiasis (K80.-) names K80.-, 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.
Clinical InformationClinical
Cholelithiasis
presence or formation of gallstones in the biliary tract, usually in the gallbladder (cholecystolithiasis) or the common bile duct (choledocholithiasis).
Patient EducationClinical
Bile Duct Diseases
Your liver makes a digestive juice called bile. Your gallbladder stores it between meals. When you eat, your gallbladder pushes the bile into tubes called bile ducts. They carry the bile to your small intestine. The bile helps break down fat. It also helps the liver get rid of toxins and wastes.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert K80.66 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K80.66Overview
Is K80.66 (Calculus of gallbladder and bile duct with cholecystitis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report calculus of gallbladder and bile duct with acute and chronic cholecystitis without obstruction on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does K80.66 group to?
When calculus of gallbladder and bile duct with acute and chronic cholecystitis without obstruction 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.
Is K80.66 a CC or MCC?
CMS lists K80.66 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 10 closely related codes in its exclusion list.
Can K80.66 be reported with K91.86?
Not as a rule. The Excludes1 note at K80, which applies to K80.66, lists "retained cholelithiasis following cholecystectomy (K91.86)". 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).
