2026 ICD-10-CM Diagnosis Code R10.821Right upper quadrant rebound abdominal tenderness

ICD-10-CM Codes›R00–R99›R10-R19›R10

ICD-10-CM R10.821
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R10.821 is a billable ICD-10-CM diagnosis code for right upper quadrant rebound abdominal tenderness. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as rebound tenderness of right hypochondrium. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abdominal pain and other digestive/abdomen signs and symptoms.

Code Identity

ICD-10-CM Code
R10.821
Billable Status
Yes — Valid for Submission
Code Describes
Right upper quadrant rebound abdominal tenderness
Short Description
Right upper quadrant rebound abdominal tenderness
Same as the full description in the CMS dataset.
Parent Code
R10.82
Rebound abdominal tenderness

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR10-R19Symptoms and signs involving the digestive system and abdomen
CategoryR10Abdominal and pelvic pain
This CodeR10.821Right upper quadrant rebound abdominal tenderness

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Rebound tenderness of right hypochondrium
  • Rebound tenderness of right upper quadrant of abdomen
  • Tenderness of right hypochondriac region
  • Tenderness of right upper quadrant of abdomen

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Tenderness, abdominal
      • rebound
        • right upper quadrant

Clinical ClassificationClinical

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

CCSR SYM006
Abdominal pain and other digestive/abdomen signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Abdominal Pain

Your abdomen extends from below your chest to your groin. Some people call it the stomach, but your abdomen contains many other important organs. Pain in the abdomen can come from any one of them. The pain may start somewhere else, such as your chest. Severe pain doesn't always mean a serious problem.

Read the full article at MedlinePlus

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

Convert R10.821 to ICD-9-CMHistory

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

ICD-9-CM
789.61 Abdmnal tndr rt upr quad
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R10.821Overview

Is R10.821 (Rebound abdominal tenderness) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report right upper quadrant rebound abdominal tenderness on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R10.821 group to?

When right upper quadrant rebound abdominal tenderness is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R10.821 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the right upper quadrant rebound abdominal tenderness is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R10.821?

Under the General Equivalence Mappings, right upper quadrant rebound abdominal tenderness converts to ICD-9-CM 789.61 (abdmnal tndr rt upr quad). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.