2026 ICD-10-CM Diagnosis Code I82.5Z9Chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity

ICD-10-CM Codes›I00–I99›I80-I89›I82

ICD-10-CM I82.5Z9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I82.5Z9 is a billable ICD-10-CM diagnosis code for chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 299 through 301. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. Coders also document this condition as chronic deep venous thrombosis of calf. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic phlebitis; thrombophlebitis and thromboembolism.

Code Identity

ICD-10-CM Code
I82.5Z9
Billable Status
Yes — Valid for Submission
Code Describes
Chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity
Short Description
Chr emblsm and thombos unsp deep vn unsp distal low extrm
Parent Code
I82.5Z
Chronic embolism and thrombosis of unspecified deep veins of distal lower extremity

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI80-I89Diseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified
CategoryI82Other venous embolism and thrombosis
This CodeI82.5Z9Chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity

Code EditsBilling

Medicare Code Editor checks that affect claim validity for I82.5Z9.

Unspecified codes
Unspecified codes exist in the ICD-10-CM classification for circumstances when documentation in the medical record does not provide the level of detail needed to support reporting a more specific code. However, in the inpatient setting, there should generally be very limited and rare circumstances for which the laterality (right, left, bilateral) of a condition is unable to be documented and reported. The following pages contain the list of unspecified ICD-10-CM diagnosis codes for which there is a more specific code to identify laterality (right, left, bilateral) within that code family.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic deep venous thrombosis of calf

Clinical ClassificationClinical

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

CCSR CIR034
Chronic phlebitis; thrombophlebitis and thromboembolism
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Deep Vein Thrombosis

Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or thigh. If the vein swells, the condition is called thrombophlebitis. A deep vein thrombosis can break loose and cause a serious problem in the lung, called a pulmonary embolism.

Read the full article at MedlinePlus

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

Convert I82.5Z9 to ICD-9-CMHistory

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

ICD-9-CM
453.52 Ch DVT/embl dstl low ext
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 I82.5Z9Overview

Is I82.5Z9 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I82.5Z9 group to?

When chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity is the principal diagnosis on an inpatient stay, it groups to MS-DRG 299, 300, 301, with relative weights from 0.7197 to 1.6327 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I82.5Z9?

Under the General Equivalence Mappings, chronic embolism and thrombosis of unspecified deep veins of unspecified distal lower extremity converts to ICD-9-CM 453.52 (ch DVT/embl dstl low ext). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.