2026 ICD-10-CM Diagnosis Code T80.818AExtravasation of other vesicant agent, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T80

ICD-10-CM T80.818A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T80.818A is a billable ICD-10-CM diagnosis code for extravasation of other vesicant agent, 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 314 through 316, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 4 closely related codes. Coders also document this condition as extravasation of intravenous contrast medium. 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
T80.818A
Billable Status
Yes — Valid for Submission
Code Describes
Extravasation of other vesicant agent, initial encounter
Short Description
Extravasation of other vesicant agent, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T80.818
Extravasation of other vesicant agent

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT80Complications following infusion, transfusion and therapeutic injection
This CodeT80.818AExtravasation of other vesicant agent, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Extravasation of intravenous contrast medium
  • Injection site extravasation
  • Leakage of radio-opaque material

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications following infusion, transfusion and therapeutic injection (T80). 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

Convert T80.818A to ICD-9-CMHistory

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

ICD-9-CM
999.82 Extravasn vesicant NEC
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 T80.818AOverview

What is the ICD-10 code for extravasation of other vesicant agent, initial encounter?

The ICD-10-CM code for extravasation of other vesicant agent, initial encounter is T80.818A (sometimes written as T80818A). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is T80.818A (Extravasation of other vesicant agent) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report extravasation of other vesicant agent, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T80.818A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for extravasation of other vesicant agent, such as an emergency visit or first evaluation.

What MS-DRG does T80.818A group to?

When extravasation of other vesicant agent, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, 791, 793, with relative weights from 0.6821 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T80.818A a CC or MCC?

CMS lists T80.818A as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 4 closely related codes in its exclusion list.