If you’re searching for thrombosis and ICD-10 classification, you probably need the right diagnostic code — fast. Here’s the short version: thrombosis codes live primarily in the I80–I82 range (venous) and I74 (arterial) within ICD-10-CM. But the system is far more granular than that, and picking the wrong code can mean claim denials, inaccurate medical records, or missed quality metrics. Below, I’ve mapped out every major thrombosis ICD-10 code you’re likely to encounter, organized by type and anatomic location.
As a hematologist, I spend a significant chunk of my day thinking about clot classification — not just for billing, but because the ICD-10 code you assign directly shapes how a patient’s risk is tracked over time. A patient coded with I26.99 (pulmonary embolism without acute cor pulmonale) gets flagged very differently than one coded with I82.401 (acute DVT of the right femoral vein). Precision matters here.
ICD-10 Codes for Venous Thrombosis (DVT)
Deep vein thrombosis (DVT) is the most commonly coded thrombotic condition in clinical practice, affecting roughly 1–2 per 1,000 adults annually in the U.S. ICD-10 requires you to specify three things: acuity (acute vs. chronic), anatomic site, and laterality (right, left, or bilateral).
| Condition | ICD-10 Code | Key Details |
|---|---|---|
| Acute DVT, femoral vein (right) | I82.411 | Specify laterality: .411 right, .412 left, .413 bilateral |
| Acute DVT, popliteal vein (left) | I82.432 | Common post-surgical site |
| Acute DVT, iliac vein (right) | I82.421 | Often associated with May-Thurner syndrome on left (.422) |
| Acute DVT, tibial vein (right) | I82.441 | Distal DVT; treatment approach may differ |
| Chronic DVT, femoral vein (left) | I82.512 | Used for established/old DVT still present on imaging |
| DVT of lower extremity, unspecified | I82.40- | Avoid when possible — specificity improves reimbursement |
| Superficial thrombophlebitis, lower extremity | I80.0–I80.3 | Not the same as DVT; carries different risk profile |
Pro tip: The fifth character is where laterality lives. Forgetting it is one of the most common coding errors I see. If imaging says “left popliteal DVT,” code I82.432 — not the unspecified version.
ICD-10 Codes for Pulmonary Embolism
Pulmonary embolism (PE) kills an estimated 100,000–300,000 Americans per year, making accurate coding clinically and epidemiologically significant. PE codes fall under I26.
- I26.01 — Septic pulmonary embolism with acute cor pulmonale
- I26.02 — Saddle embolus of pulmonary artery with acute cor pulmonale
- I26.09 — Other pulmonary embolism with acute cor pulmonale
- I26.90 — Septic pulmonary embolism without acute cor pulmonale
- I26.92 — Saddle embolus without acute cor pulmonale
- I26.99 — Other pulmonary embolism without acute cor pulmonale (this is your workhorse code)
The distinction between “with” and “without” acute cor pulmonale isn’t just academic — it changes risk stratification and often determines ICU-level care vs. floor admission.
ICD-10 Codes for Arterial Thrombosis
Arterial thrombosis codes cluster under I74 (arterial embolism and thrombosis) and various organ-specific codes when the thrombosis causes an end-organ event like stroke or MI.
| Condition | ICD-10 Code |
|---|---|
| Embolism/thrombosis of abdominal aorta | I74.01 |
| Embolism/thrombosis of iliac artery | I74.5 |
| Embolism/thrombosis of arteries of upper extremities | I74.2 |
| Embolism/thrombosis of arteries of lower extremities | I74.3 |
| Acute myocardial infarction (Type 1, STEMI, anterior wall) | I21.01 |
| Cerebral infarction due to thrombosis of middle cerebral artery | I63.311–I63.319 |
When arterial thrombosis causes a stroke or heart attack, you code the end-organ event as the primary diagnosis rather than using the generic I74 codes. The thrombosis is implicit in the MI or stroke code.
Special Situations: Thrombosis ICD-10 Codes People Miss
Portal Vein Thrombosis
Coded as I81 (portal vein thrombosis). Common in patients with cirrhosis or hepatocellular carcinoma. This is a single code — no laterality or acuity modifier needed.
Cerebral Venous Sinus Thrombosis (CVST)
Falls under I67.6 (nonpyogenic thrombosis of intracranial venous system). Often underdiagnosed, CVST has gained renewed attention since 2021 due to rare vaccine-associated cases.
Thrombosis of Cardiac Devices
Mechanical heart valve thrombosis uses T82.867A (thrombosis due to cardiac prosthetic devices, initial encounter). Don’t forget the seventh character for encounter type.
Hypercoagulable States (Underlying Cause)
When coding thrombosis, you’ll often need a secondary code for the underlying thrombophilia:
- D68.51 — Activated protein C resistance (Factor V Leiden)
- D68.52 — Prothrombin gene mutation
- D68.59 — Other primary thrombophilia (Protein C, Protein S deficiency)
- D68.61 — Antiphospholipid syndrome
Common Coding Mistakes to Avoid
- Using unspecified codes when imaging data is available. If CT says “left popliteal DVT,” don’t code I82.409. Payers increasingly reject unspecified codes.
- Confusing acute vs. chronic DVT. Acute DVT lives in I82.40x; chronic DVT in I82.50x. A DVT diagnosed 6 months ago that’s still present on ultrasound is chronic.
- Forgetting to code both DVT and PE when both are present. These are separate codes. Document both.
- Missing the thrombophilia code. If a patient has Factor V Leiden and develops DVT, code both. It affects long-term anticoagulation decisions and future risk assessment.
Frequently Asked Questions
What is the most commonly used ICD-10 code for DVT?
I82.401 (acute embolism and thrombosis of unspecified deep veins of right lower extremity) is frequently used, but best practice is to specify the exact vein — femoral (I82.411), popliteal (I82.431), or tibial (I82.441) — based on imaging findings.
Is there a single ICD-10 code for “thrombosis”?
No. ICD-10 doesn’t have one catch-all thrombosis code. You must specify venous vs. arterial, acute vs. chronic, anatomic location, and laterality. The closest to a general code is I82.90 (acute embolism and thrombosis of unspecified vein), but this should be a last resort.
How do I code thrombosis in pregnancy?
Pregnancy-related thrombosis uses O22.3x (deep phlebothrombosis in pregnancy) for antepartum DVT and O87.1 for postpartum DVT. These are separate from the I80–I82 codes. The “x” placeholder indicates trimester.
What’s the difference between I80 and I82 codes?
I80 covers phlebitis and thrombophlebitis (inflammation of superficial or deep veins with clot). I82 covers embolism and thrombosis of veins more broadly, including non-inflammatory clot. In practice, most DVTs get I82 codes; I80 is used when there’s a prominent inflammatory component or superficial vein involvement.
Does ICD-10 distinguish between provoked and unprovoked thrombosis?
Not directly. ICD-10 codes describe the location and acuity of thrombosis, not the trigger. However, you can capture the provoking factor with secondary codes — for example, Z79.01 (long-term use of anticoagulants) or Z87.111 (personal history of pulmonary embolism) for recurrence context.
Key Takeaways
- Thrombosis ICD-10 codes span multiple categories: I74 (arterial), I80–I82 (venous), I26 (PE), and I81 (portal vein).
- Always specify acuity, anatomic site, and laterality — it reduces denials and improves data quality.
- Code underlying thrombophilias (D68.5x, D68.6x) as secondary diagnoses whenever documented.
- Pregnancy-related thrombosis has its own code set under O22–O87 — don’t use the standard I-series codes.
- When thrombosis causes a stroke or MI, code the end-organ event as primary, not the generic thrombosis code.
