2026 ICD-10-CM Diagnosis Code K40.21Bilateral inguinal hernia, without obstruction or gangrene, recurrent

ICD-10-CM Codes›K00–K95›K40-K46›K40

ICD-10-CM K40.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K40.21 is a billable ICD-10-CM diagnosis code for bilateral inguinal hernia, without obstruction or gangrene, recurrent. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. Coders also document this condition as bilateral recurrent inguinal hernia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abdominal hernia.

Code Identity

ICD-10-CM Code
K40.21
Billable Status
Yes — Valid for Submission
Code Describes
Bilateral inguinal hernia, without obstruction or gangrene, recurrent
Short Description
Bilateral inguinal hernia, w/o obst or gangrene, recurrent
Parent Code
K40.2
Bilateral inguinal hernia, without obstruction or gangrene

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK40-K46Hernia
CategoryK40Inguinal hernia
This CodeK40.21Bilateral inguinal hernia, without obstruction or gangrene, recurrent

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral recurrent inguinal hernia
  • Recurrent left inguinal hernia
  • Recurrent right inguinal hernia

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.

    • Hernia, hernial(acquired) (recurrent)
      • inguinal (direct) (external) (funicular) (indirect) (internal) (oblique) (scrotal) (sliding)
        • bilateral
          • recurrent

Clinical ClassificationClinical

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

CCSR DIG010
Abdominal hernia
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hernia

A hernia happens when part of an internal organ or tissue bulges through a weak area of muscle. Most hernias are in the abdomen.

Read the full article at MedlinePlus

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

Convert K40.21 to ICD-9-CMHistory

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

ICD-9-CM
550.93 Recur bilat inguin hern
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 K40.21Overview

Is K40.21 (Bilateral inguinal hernia, without obstruction or gangrene) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report bilateral inguinal hernia, without obstruction or gangrene, recurrent on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K40.21 group to?

When bilateral inguinal hernia, without obstruction or gangrene, recurrent is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K40.21?

Under the General Equivalence Mappings, bilateral inguinal hernia, without obstruction or gangrene, recurrent converts to ICD-9-CM 550.93 (recur bilat inguin hern). 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.