2027 ICD-10-CM Diagnosis Code I74.9Embolism and thrombosis of unspecified artery

ICD-10-CM Codes›I00–I99›I70-I79›I74

ICD-10-CM I74.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I74.9 is a billable ICD-10-CM diagnosis code for embolism and thrombosis of unspecified artery. 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 63 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Aortic and peripheral arterial embolism or thrombosis.

For Medicare Advantage risk adjustment, I74.9 maps to CMS-HCC Category 264 (Vascular Disease with Complications) under the V28 model, adding a risk factor of about 0.455 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
I74.9
Billable Status
Yes — Valid for Submission
Code Describes
Embolism and thrombosis of unspecified artery
Short Description
Embolism and thrombosis of unspecified artery
Same as the full description in the CMS dataset.
Parent Code
I74
Arterial embolism and thrombosis

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI74Arterial embolism and thrombosis
This CodeI74.9Embolism and thrombosis of unspecified artery

Medicare Risk Adjustment (HCC)Billing

I74.9 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 264— Vascular Disease with Complications
Payment HCC · PY 2027 one of 71 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.455
community, non-dual, aged · ranges 0.338–0.622 across segments
Hierarchy
Superseded by HCC 263
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 107
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 107 · ESRD (V21): HCC 107 · ESRD (V24): HCC 107
ESRD V21 weights: 0.126 dialysis, 0.300–0.431 functioning graft · ESRD V24 weights: 0.144 dialysis, 0.324–0.586 functioning graft
Part D (RxHCC)
Not mapped
I74.9 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.

  • Acute occlusion of artery due to thromboembolus
  • Acute occlusion of artery due to thrombosis
  • Acute occlusion of peripheral artery due to thrombosis
  • Arterial embolism
  • Arterial embolus and thrombosis
  • Arterial insufficiency of flap
  • Arterial obstruction due to paradoxical embolism
  • Arterial obstruction due to thrombotic embolism from aneurysm of artery
  • Arterial obstruction due to thrombotic embolism from aneurysm of ventricle
  • Arterial obstruction due to thrombotic embolism from mural thrombus of heart
  • Arterial thrombosis
  • Arterial thrombosis of flap
  • Arteriovenous fistula thrombosis
  • Atherosclerotic plaque disruption with thrombosis of artery
  • Barium sulfate embolism
  • Cerebrovascular disorder due to paradoxical embolus
  • Congenital arteriovenous fistula thrombosis
  • Drug-induced embolism
  • Embolic infarction
  • Embolism
  • Embolism due to cardiac myxoma
  • Embolism due to malignant neoplasm
  • Embolism due to non-infective heart valve vegetations
  • Embolism from atrium of heart
  • Embolism from heart
  • Grange syndrome
  • Hereditary dysplasia of blood vessel
  • Methyl methacrylate embolism
  • Microvascular embolism of arteriole
  • Obstetrical blood clot embolism
  • Recurrent thromboembolism
  • Retraction of blood clot
  • Talc embolism
  • Thromboembolic disorder
  • Thromboembolism due to mural thrombus
  • Thromboembolism due to vegetative endocarditis of heart valve
  • Thromboembolism following infusion, perfusion AND/OR transfusion
  • Thromboembolism from prosthetic heart valve
  • Thrombotic embolism from cardiac atrium
  • Thrombotic embolism from cardiac ventricle
  • Thrombotic infarction
  • Trunk arterial embolus
  • Tumor embolus

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I74.9: its own notes plus those printed at I74 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 I74 Arterial embolism and thrombosis applies to 11 codes
  • embolic infarction
  • embolic occlusion
  • thrombotic infarction
  • thrombotic occlusion

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 I74 Arterial embolism and thrombosis applies to 11 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.-)

Code First

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

From I74 Arterial embolism and thrombosis applies to 11 codes
  • embolism and thrombosis complicating abortion or ectopic or molar pregnancy (O00-O07, O08.2)
  • embolism and thrombosis complicating pregnancy, childbirth and the puerperium (O88.-)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I74.9, its category, or a range that includes it.

Use Additional Code 1

These codes say to use an additional code from the note, and I74.9 is one of the codes named.

  • I76 Septic arterial embolism
    code to identify the site of the embolism (I74.-) names I74.-, 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 CIR030
Aortic and peripheral arterial embolism or thrombosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Embolism

    blocking of a blood vessel by an embolus which can be a blood clot or other undissolved material in the blood stream.

Convert I74.9 to ICD-9-CMHistory

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

ICD-9-CM
444.9 Arterial embolism NOS
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 I74.9Overview

What is the ICD-10 code for embolism and thrombosis of unspecified artery?

The ICD-10-CM code for embolism and thrombosis of unspecified artery is I74.9 (sometimes written as I749). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is I74.9 (Arterial embolism and thrombosis) a billable code?

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

What MS-DRG does I74.9 group to?

When embolism and thrombosis of unspecified artery 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 I74.9 a CC or MCC?

CMS lists I74.9 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 63 closely related codes in its exclusion list.

What is coded first with I74.9?

The Code First note at I74, which applies to I74.9, reads: embolism and thrombosis complicating abortion or ectopic or molar pregnancy (O00-O07, O08.2); embolism and thrombosis complicating pregnancy, childbirth and the puerperium (O88.-). When one of these applies, it is sequenced before I74.9.

What HCC is I74.9?

I74.9 (embolism and thrombosis of unspecified artery) maps to CMS-HCC Category 264 (Vascular Disease with Complications), commonly written as HCC 264, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 107 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does I74.9 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, I74.9 adds a risk adjustment factor of about 0.455 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.338 to 0.622 depending on the payment segment). A more severe related category (HCC 263) supersedes it when both are reported. See the full factor table on the HCC 264 category page.