2027 ICD-10-CM Diagnosis Code I73.1Thromboangiitis obliterans [Buerger's disease]

ICD-10-CM Codes›I00–I99›I70-I79›I73

ICD-10-CM I73.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I73.1 is a billable ICD-10-CM diagnosis code for thromboangiitis obliterans [Buerger's disease]. 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. Coders also document this condition as neuropathy in thromboangiitis obliterans. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Peripheral and visceral vascular disease.

I73.1 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 108 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 108, ESRD (V21) category 108, and ESRD (V24) category 108 for payment year 2027.

Code Identity

ICD-10-CM Code
I73.1
Billable Status
Yes — Valid for Submission
Code Describes
Thromboangiitis obliterans [Buerger's disease]
Short Description
Thromboangiitis obliterans [Buerger's disease]
Same as the full description in the CMS dataset.
Parent Code
I73
Other peripheral vascular diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI73Other peripheral vascular diseases
This CodeI73.1Thromboangiitis obliterans [Buerger's disease]

Medicare Risk Adjustment (HCC)Billing

I73.1 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 108
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
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)
Not mapped
I73.1 does not risk-adjust in the RxHCC prescription drug model

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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neuropathy in thromboangiitis obliterans
  • Presenile gangrene
  • Thromboangiitis
  • Thromboangiitis obliterans

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I73.1: its own notes plus those printed at I73 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

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 I73 Other peripheral vascular diseases applies to 6 codes
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.-)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I73.1, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming I73.1: they are not reported together with it, unless the two conditions are unrelated.

  • I96 Gangrene, not elsewhere classified
    gangrene in other peripheral vascular diseases (I73.-) names I73.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR CIR026
Peripheral and visceral vascular disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Thromboangiitis Obliterans

    a non-atherosclerotic, inflammatory thrombotic disease that commonly involves small and medium-sized arteries or veins in the extremities. it is characterized by occlusive thrombosis and fibrosis in the vascular wall leading to digital and limb ischemia and ulcerations. thromboangiitis obliterans is highly associated with tobacco smoking.

Patient EducationClinical

Vasculitis

Vasculitis is an inflammation of the blood vessels. It happens when the body's immune system attacks the blood vessel by mistake. It can happen because of an infection, a medicine, or another disease. The cause is often unknown.

Read the full article at MedlinePlus

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

Convert I73.1 to ICD-9-CMHistory

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

ICD-9-CM
443.1 Thromboangiit obliterans
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I73.1Overview

What is the ICD-10 code for thromboangiitis obliterans [Buerger's disease]?

The ICD-10-CM code for thromboangiitis obliterans [Buerger's disease] is I73.1 (sometimes written as I731). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I73.1 (Other peripheral vascular diseases) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report thromboangiitis obliterans [Buerger's disease] on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does I73.1 group to?

When thromboangiitis obliterans [Buerger's disease] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 301, 300, 299, with relative weights from 0.7132 to 1.5840 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I73.1?

Under the General Equivalence Mappings, thromboangiitis obliterans [Buerger's disease] converts to ICD-9-CM 443.1 (thromboangiit obliterans). The mapping is a direct match.

Does I73.1 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. I73.1 mapped to HCC 108 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 108 (Vascular Disease), ESRD (V21) category 108 (Vascular Disease), and ESRD (V24) category 108 (Vascular Disease).