2026 ICD-10-CM Diagnosis Code T88.0XXSInfection following immunization, sequela

ICD-10-CM Codes›S00–T88›T80-T88›T88

ICD-10-CM T88.0XXS
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T88.0XXS is a billable ICD-10-CM diagnosis code for infection following immunization, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. Coders also document this condition as COVID-19. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication, sequela.

Code Identity

ICD-10-CM Code
T88.0XXS
Billable Status
Yes — Valid for Submission
Code Describes
Infection following immunization, sequela
Short Description
Infection following immunization, sequela
Same as the full description in the CMS dataset.
Parent Code
T88.0
Infection following immunization

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT88Other complications of surgical and medical care, not elsewhere classified
This CodeT88.0XXSInfection following immunization, sequela

Present on Admission (POA)Billing

T88.0XXS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • COVID-19
  • Infection following immunization
  • Primary immunodeficiency with post-measles-mumps-rubella vaccine viral infection
  • SARS-CoV-2 breakthrough infection
  • Sepsis following infusion, injection, transfusion AND/OR vaccination

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Other complications of surgical and medical care, not elsewhere classified (T88). 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 INJ076
Complication, sequela
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Vaccines

Vaccines are injections (shots), liquids, pills, or nasal sprays that you take to teach your body's immune system to recognize and defend against harmful germs. For example, there are vaccines to protect against diseases caused by:

The full article covers:

  • What are vaccines?
  • What are the types of vaccines?
  • What happens in an immune response?
  • What are immunization and vaccination?
  • Why are vaccines important?
  • What is community immunity?
  • Are vaccines safe?
  • What is a vaccine schedule?

Read the full article at MedlinePlus

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

Convert T88.0XXS to ICD-9-CMHistory

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

ICD-9-CM
909.3 Late eff surg/med compl
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 T88.0XXSOverview

Is T88.0XXS (Infection following immunization) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report infection following immunization, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T88.0XXS mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the infection following immunization itself has resolved, not the original event.

What MS-DRG does T88.0XXS group to?

When infection following immunization, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T88.0XXS exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for infection following immunization, sequela on inpatient claims.

What is the ICD-9 equivalent of T88.0XXS?

Under the General Equivalence Mappings, infection following immunization, sequela converts to ICD-9-CM 909.3 (late eff surg/med compl). 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.