2027 ICD-10-CM Diagnosis Code B26.3Mumps pancreatitis

ICD-10-CM Codes›A00–B99›B25-B34›B26

ICD-10-CM B26.3
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

B26.3 is a billable ICD-10-CM diagnosis code for mumps pancreatitis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 438 through 440, 791, 793. 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 23 closely related codes. Coders also document this condition as infectious pancreatitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Pancreatic disorders (excluding diabetes) and Viral infection.

Code Identity

ICD-10-CM Code
B26.3
Billable Status
Yes — Valid for Submission
Code Describes
Mumps pancreatitis
Short Description
Mumps pancreatitis
Same as the full description in the CMS dataset.
Parent Code
B26
Mumps

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB25-B34Other viral diseases
CategoryB26Mumps
This CodeB26.3Mumps pancreatitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infectious pancreatitis
  • Mumps pancreatitis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to B26.3: its own notes plus those printed at B26 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From B26 Mumps applies to 11 codes
  • epidemic parotitis
  • infectious parotitis
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

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 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

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

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name B26.3, its category, or a range that includes it.

Applicable To 1

These notes mention B26.3.

  • O98.5 Other viral diseases complicating pregnancy, childbirth and the puerperium
    Conditions in A80-B09, B25-B34, R87.81-, R87.82- names B25-B34, which includes this code

Excludes1 3

These codes carry an Excludes1 note naming B26.3: they are not reported together with it, unless the two conditions are unrelated.

  • K87 Disorders of gallbladder, biliary tract and pancreas in diseases classified elsewhere
    mumps pancreatitis (B26.3)
  • K11.2 Sialoadenitis
    epidemic parotitis (B26.-) names B26.-, which includes this code
  • K11.2 Sialoadenitis
    mumps (B26.-) names B26.-, 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 DIG020
Pancreatic disorders (excluding diabetes)
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF008
Viral infection
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Mumps

    an acute infectious disease caused by rubulavirus, spread by direct contact, airborne droplet nuclei, fomites contaminated by infectious saliva, and perhaps urine, and usually seen in children under the age of 15, although adults may also be affected. (from dorland, 28th ed)

Patient EducationClinical

Mumps

Mumps is an illness caused by the mumps virus. It starts with:

Read the full article at MedlinePlus

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

Convert B26.3 to ICD-9-CMHistory

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

ICD-9-CM
072.3 Mumps pancreatitis
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 B26.3Overview

What is the ICD-10 code for mumps pancreatitis?

The ICD-10-CM code for mumps pancreatitis is B26.3 (sometimes written as B263). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is B26.3 (Mumps) a billable code?

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

What MS-DRG does B26.3 group to?

When mumps pancreatitis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 440, 438, 439, with relative weights from 0.5966 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is B26.3 a CC or MCC?

CMS lists B26.3 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 23 closely related codes in its exclusion list.

What is the ICD-9 equivalent of B26.3?

Under the General Equivalence Mappings, mumps pancreatitis converts to ICD-9-CM 072.3 (mumps pancreatitis). The mapping is a direct match.