2027 ICD-10-CM Diagnosis Code I80.249Phlebitis and thrombophlebitis of unspecified peroneal vein

ICD-10-CM Codes›I00–I99›I80-I89›I80

ICD-10-CM I80.249
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I80.249 is a billable ICD-10-CM diagnosis code for phlebitis and thrombophlebitis of unspecified peroneal vein. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 299 through 301, 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 100 closely related codes. The code is flagged as an unspecified code, since codes identifying laterality exist in the same family. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Acute phlebitis; thrombophlebitis and thromboembolism.

For Medicare Advantage risk adjustment, I80.249 maps to CMS-HCC Category 267 (Deep Vein Thrombosis and Pulmonary Embolism) under the V28 model, adding a risk factor of about 0.294 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
I80.249
Billable Status
Yes — Valid for Submission
Code Describes
Phlebitis and thrombophlebitis of unspecified peroneal vein
Short Description
Phlebitis and thrombophlebitis of unspecified peroneal vein
Same as the full description in the CMS dataset.
Parent Code
I80.24
Phlebitis and thrombophlebitis of peroneal vein

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI80-I89Diseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified
CategoryI80Phlebitis and thrombophlebitis
This CodeI80.249Phlebitis and thrombophlebitis of unspecified peroneal vein

Code EditsBilling

Medicare Code Editor checks that affect claim validity for I80.249.

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.

Medicare Risk Adjustment (HCC)Billing

I80.249 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 267— Deep Vein Thrombosis and Pulmonary Embolism
Payment HCC · PY 2027 one of 167 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.294
community, non-dual, aged · ranges 0.245–0.568 across segments
Hierarchy
Top of its hierarchy
HCC 267 is not superseded by any other condition category
Prior Model (CMS-HCC V24)
HCC 108
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 108 · ESRD (V21): HCC 108 · ESRD (V24): HCC 108
ESRD V21 weights: 0.065 dialysis, 0.086–0.271 functioning graft · ESRD V24 weights: 0.073 dialysis, 0.074–0.287 functioning graft
Part D (RxHCC)
RxHCC 215 — Venous Thromboembolism
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I80.249: its own notes plus those printed at I80 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From I80 Phlebitis and thrombophlebitis applies to 39 codes
  • endophlebitis
  • inflammation, vein
  • periphlebitis
  • suppurative phlebitis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From I80 Phlebitis and thrombophlebitis applies to 39 codes

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Code First

The underlying condition named in the note is sequenced before this code.

From I80 Phlebitis and thrombophlebitis applies to 39 codes
  • if applicable: phlebitis and thrombophlebitis complicating abortion, ectopic or molar pregnancy (O00-O07, O08.7)
  • phlebitis and thrombophlebitis complicating pregnancy, childbirth and the puerperium (O22.-, O87.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

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

CCSR CIR033
Acute 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.

Code History & ChangesHistory

Replacement I80.249 replaces the following previously assigned code(s):

  • I80.299 - Phlebitis and thombophlb of deep vessels of unsp low extrm
FY 2020AddedAdded to the ICD-10-CM code setEffective October 1, 2019.
FY 2021–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I80.249Overview

What is the ICD-10 code for phlebitis and thrombophlebitis of unspecified peroneal vein?

The ICD-10-CM code for phlebitis and thrombophlebitis of unspecified peroneal vein is I80.249 (sometimes written as I80249). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I80.249 (Phlebitis and thrombophlebitis of peroneal vein) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report phlebitis and thrombophlebitis of unspecified peroneal vein on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I80.249 group to?

When phlebitis and thrombophlebitis of unspecified peroneal vein is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 301, 300, 299, with relative weights from 0.7132 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Is I80.249 a CC or MCC?

CMS lists I80.249 as a CC (complication or comorbidity) for FY 2027. 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 100 closely related codes in its exclusion list.

Can I80.249 be reported with a code from I82.4?

Not as a rule. The Excludes1 note at I80, which applies to I80.249, lists "venous embolism and thrombosis of lower extremities (I82.4-, I82.5-, I82.81-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What HCC is I80.249?

I80.249 (phlebitis and thrombophlebitis of unspecified peroneal vein) maps to CMS-HCC Category 267 (Deep Vein Thrombosis and Pulmonary Embolism), commonly written as HCC 267, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 108 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 215.

Does I80.249 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, I80.249 adds a risk adjustment factor of about 0.294 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.245 to 0.568 depending on the payment segment). HCC 267 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 267 category page.