2026 ICD-10-CM Diagnosis Code R19.04Left lower quadrant abdominal swelling, mass and lump

ICD-10-CM Codes›R00–R99›R10-R19›R19

ICD-10-CM R19.04
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R19.04 is a billable ICD-10-CM diagnosis code for left lower quadrant abdominal swelling, mass and lump. 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 iliac fossa abdominal mass. 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
R19.04
Billable Status
Yes — Valid for Submission
Code Describes
Left lower quadrant abdominal swelling, mass and lump
Short Description
Left lower quadrant abdominal swelling, mass and lump
Same as the full description in the CMS dataset.
Parent Code
R19.0
Intra-abdominal and pelvic swelling, mass and lump

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR10-R19Symptoms and signs involving the digestive system and abdomen
CategoryR19Other symptoms and signs involving the digestive system and abdomen
This CodeR19.04Left lower quadrant abdominal swelling, mass and lump

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Iliac fossa abdominal mass
  • Left iliac fossa mass
  • Mass fills left half of abdomen
  • Mass fills left lower quadrant of abdomen
  • Mass fills lower half of abdomen
  • Mass fills part of left lower quadrant of abdomen
  • Mass of left lower quadrant of abdomen
  • Mass of left lower quadrant of abdominal wall

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.

    • Mass
      • abdominal
        • left lower 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

Convert R19.04 to ICD-9-CMHistory

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

ICD-9-CM
789.34 Abdmnal mass lt lwr quad
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R19.04Overview

Is R19.04 (Intra-abdominal and pelvic swelling, mass and lump) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report left lower quadrant abdominal swelling, mass and lump on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R19.04 group to?

When left lower quadrant abdominal swelling, mass and lump 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 R19.04 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the left lower quadrant abdominal swelling, mass and lump is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R19.04?

Under the General Equivalence Mappings, left lower quadrant abdominal swelling, mass and lump converts to ICD-9-CM 789.34 (abdmnal mass lt lwr quad). The mapping is a direct match.

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.