2026 ICD-10-CM Diagnosis Code T81.42XAInfection following a procedure, deep incisional surgical site, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T81

ICD-10-CM T81.42XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T81.42XA is a billable ICD-10-CM diagnosis code for infection following a procedure, deep incisional surgical site, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 856 through 858, 862 through 863. Coders also document this condition as deep incisional surgical site infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.

Code Identity

ICD-10-CM Code
T81.42XA
Billable Status
Yes — Valid for Submission
Code Describes
Infection following a procedure, deep incisional surgical site, initial encounter
Short Description
Infct fol a procedure, deep incisional surgical site, init
Parent Code
T81.42
Infection following a procedure, deep incisional surgical site

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT81Complications of procedures, not elsewhere classified
This CodeT81.42XAInfection following a procedure, deep incisional surgical site, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Deep incisional surgical site infection
  • Postoperative wound infection
  • Postoperative wound infection-deep

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications of procedures, not elsewhere classified (T81). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ037
Complication of other surgical or medical care, injury, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

After Surgery

After any operation, you'll have some side effects. There is usually some pain with surgery. There may also be swelling and soreness around the area that the surgeon cut. Your surgeon can tell you which side effects to expect.

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement T81.42XA replaces the following previously assigned code(s):

  • T81.4XXA - Infection following a procedure, initial encounter
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T81.42XAOverview

Is T81.42XA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report infection following a procedure, deep incisional surgical site, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T81.42XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for infection following a procedure, deep incisional surgical site, such as an emergency visit or first evaluation.

What MS-DRG does T81.42XA group to?

When infection following a procedure, deep incisional surgical site, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 856, 857, 858, 862, 863, with relative weights from 0.9979 to 4.5487 depending on complications. Higher weights mean higher Medicare reimbursement.

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.