Peripheral arterial disease (PAD), also known as peripheral vascular disease, is a common circulatory disorder where narrowed arteries reduce blood flow to the limbs. According to the Centers for Disease Control and Prevention (CDC), PAD affects more than 6.5 million adults in the United States over the age of 40, making it a major public health concern.
From a billing perspective, PAD is also one of the most heavily scrutinized conditions. The Centers for Medicare & Medicaid Services (CMS) frequently audits vascular claims due to the high costs associated with imaging, revascularization procedures, and long-term management. Using the correct ICD-10 code for peripheral arterial disease (I73.9) is essential to ensure proper reimbursement and avoid denials.
Did You Know? The American Heart Association (AHA) estimates that patients with PAD have a six to seven times higher risk of cardiovascular events, which increases the medical necessity for frequent evaluations and interventions. This makes accurate ICD-10/CPT linkage vital for payer approval.
What Is Peripheral Arterial Disease and What Symptoms Should Be Documented?
Peripheral arterial disease occurs when atherosclerosis narrows or blocks arteries, typically in the legs. Clinically, patients present with claudication (leg pain while walking), non-healing wounds, cold extremities, or in severe cases, critical limb ischemia.
But for billing and compliance, documentation should capture more than clinical symptoms. The National Institutes of Health (NIH) advises providers to document:
What Details of Peripheral Arterial Disease Must Be Documented?
Peripheral arterial disease is not a one-size-fits-all diagnosis. For payers, specificity in documentation is what drives ICD-10 code selection, CPT linkage, and medical necessity approval. If a provider only documents “PAD” without detail, coders are forced to default to I73.9 (unspecified peripheral vascular disease), a red flag for denials. The Centers for Medicare & Medicaid Services (CMS) repeatedly stresses that unspecified PAD coding leads to improper payments and recoupments. Here’s how each documentation element should be captured:
| Element | Clinical Explanation | ICD-10 & Billing Impact | Denial Risk if Missing |
|---|---|---|---|
| Type of PAD (atherosclerosis of extremities, intermittent claudication, critical ischemia) | PAD ranges from mild narrowing with exertional pain (claudication) to life-threatening ischemia with ulcers or gangrene. | Type determines whether coders assign I70.2xx (with claudication), I70.23x (with ulceration), or I70.26x (with gangrene). | Claim defaults to I73.9 unspecified, which payers may deny as “non-specific.” |
| Location of Disease (femoral, popliteal, iliac, multiple sites) | PAD may affect one vessel (femoral) or multiple segments. Laterality (right, left, bilateral) also matters. | Specificity enables CPT linkage for angioplasty (37225 femoral, 37226 iliac). | Procedures like stenting can be denied if the operative site isn’t documented. |
| Severity of Symptoms (mild claudication vs gangrene) | Severity ranges from pain with walking → rest pain → tissue loss or gangrene. | Severity level impacts both ICD-10 coding and medical necessity for invasive interventions. | Angioplasty or bypass may be denied without clear symptom severity progression. |
| Associated Risk Factors (diabetes, smoking, hyperlipidemia, hypertension) | PAD rarely exists alone; comorbidities drive progression and justify aggressive management. | Documenting risk factors supports chronic care management CPT 99490 and strengthens inpatient justification. | Without risk factors, claims may be denied for “lack of medical necessity” for imaging or revascularization. |
Did You Know? According to the American Heart Association (AHA), 1 in 3 people with diabetes over age 50 has PAD, making comorbidity documentation critical for accurate coding and billing.
What Does The ICD-10 Code for Peripheral Arterial Mean?
The primary ICD-10 code for peripheral arterial disease (PAD) is I73.9 Peripheral vascular disease, unspecified. This code is often used when a provider documents “peripheral vascular disease” or “PAD” without specifying the type, location, or complications. While technically correct, I73.9 is considered a non-specific code and is one of the most common reasons for claim denials. The World Health Organization ICD-10 database makes clear that I73.9 should be used only if no further detail is available.
In most cases, payers and auditors expect providers to assign a more detailed code from the I70.x series (Atherosclerosis of arteries of extremities), which specify: Whether the patient has claudication, lceration, or gangrene, Laterality (right, left, bilateral) and Location of the arterial disease (femoral, popliteal, iliac).
The Centers for Medicare & Medicaid Services (CMS) states that “unspecified circulatory system codes” such as I73.9 can trigger medical necessity denials for procedures like angioplasty, duplex ultrasound, and bypass surgery.
| ICD-10 Code | Description | When to Use | Compliance Impact |
|---|---|---|---|
| I73.9 | Peripheral vascular disease, unspecified | When provider only documents “PAD” without detail. | High denial risk. Payers may reject claims for imaging or revascularization. |
| I70.211 | Atherosclerosis of native arteries of extremities with intermittent claudication, right leg | For PAD patients with exertional leg pain (claudication). | Supports E/M visits, exercise therapy, and medication management. |
| I70.233 | Atherosclerosis of native arteries of extremities with ulceration, left leg | For PAD with non-healing wounds or ulcers. | Justifies wound care CPT 11042, 11043 and vascular procedures. |
| I70.261 | Atherosclerosis of native arteries of extremities with gangrene, right leg | For PAD with critical ischemia and tissue loss. | Supports bypass or amputation; strong medical necessity. |
| I70.8xx | Atherosclerosis of extremities with other complications | For less common but severe PAD complications. | Reinforces medical necessity for advanced imaging and interventions. |
Did You Know? The Healthcare Financial Management Association (HFMA) reports that vascular claims coded with I73.9 have a 40% higher denial rate than those coded with I70.x series, due to “lack of specificity.”
Which ICD-10 Chapter Covers Peripheral Arterial Disease?
PAD codes are located in Chapter 9: Diseases of the Circulatory System (I00-I99). This classification matters because payers use chapter-based coverage rules to decide whether vascular imaging and revascularization procedures are reimbursable.
According to CMS’s Medicare Coverage Database, vascular procedures such as angioplasty or bypass require precise I70.x codes, not I73.9 unspecified. Misclassification under “unspecified circulatory disorders” is a common denial trigger.
| CPT Code | Service Description | When Used in PAD Billing | Compliance Notes (with Sources) |
|---|---|---|---|
| 99213 / 99214 | Outpatient E/M visits | For evaluation of PAD symptoms, medication management, risk factor counseling. | According to the CMS E/M Guidelines, documentation must include claudication, rest pain, or wounds linked to I70.x or I73.9. |
| 93925 / 93926 | Duplex scan of lower extremity arteries | Ordered for diagnosis or monitoring PAD progression. | The American College of Radiology (ACR) notes medical necessity must reflect claudication or suspected ischemia. |
| 37225 | Angioplasty, femoral/popliteal artery | Used in revascularization for symptomatic PAD. | As CMS outlines in its LCD for Lower Extremity Revascularization, documentation must prove failure of medical therapy and imaging confirmation. |
| 35371 | Femoral-popliteal bypass graft | For severe occlusive disease or limb-threatening ischemia. | Must justify with documented ischemia, ulcers, or gangrene, consistent with Medicare LCD criteria. |
| 11042 / 11043 | Wound debridement | For PAD-related non-healing ulcers. | The AMA CPT Assistant emphasizes that ulcer diagnosis must be linked directly to a PAD ICD-10 code. |
Did You Know? The American College of Cardiology (ACC) stresses that PAD is underdiagnosed and undertreated, and improper coding contributes to gaps in reimbursement for vascular procedures.
What Treatments for Peripheral Arterial Disease Are Covered and How Does This Affect Billing?
Treatment for PAD ranges from lifestyle changes and medications to invasive revascularization. The National Heart, Lung, and Blood Institute (NHLBI) outlines therapy based on severity.
| Treatment Type | When Used | Billing Impact | Documentation Needed |
|---|---|---|---|
| Lifestyle & Medical Management | Early PAD, risk factor control (smoking cessation, statins, antihypertensives). | Outpatient visits (99213/99214) + medication management. | Must link PAD diagnosis to risk factor counseling. |
| Exercise Therapy | Supervised exercise for intermittent claudication. | CPT 93668 (cardiac rehab-like services in some payers). | Document exercise protocol and PAD symptoms. |
| Medications | Antiplatelets, statins, vasodilators. | Billed under E/M visits, some require prior authorization. | Document necessity (claudication, risk of CV events). |
| Angioplasty / Stenting | For severe occlusion in femoral/popliteal arteries. | CPT 37225, 37226, etc. | Must prove failure of conservative therapy and imaging findings. |
| Bypass Surgery | For critical limb ischemia, gangrene, non-healing ulcers. | CPT 35371 (fem-pop bypass). | Documentation of ulcer/gangrene required. |
| Wound Care / Debridement | For PAD-related ulcers. | CPT 11042, 11043. | Must link ulcers directly to PAD ICD-10 code. |
How Should PAD Documentation Be Structured to Avoid Denials?
Peripheral arterial disease (PAD) is one of the most heavily audited vascular conditions because it often leads to high-cost imaging, revascularization procedures, wound care, and long-term management. Even when providers select the correct ICD-10 code for peripheral arterial disease (I73.9 or I70.x), claims are frequently denied if the supporting documentation does not clearly establish medical necessity.
The Centers for Medicare & Medicaid Services (CMS) emphasizes that claims for PAD-related procedures, such as duplex scans (93925), angioplasty (37225), or bypass surgery (35371), must be supported by detailed clinical notes. Missing details like location, laterality, or complication status can cause claims to default to I73.9 unspecified, which is one of the top denial triggers.
Similarly, the Office of Inspector General (OIG) has flagged vascular claims with incomplete documentation as a source of Medicare overpayments, putting providers at higher audit risk. Proper documentation must capture:
| Step | Action | Denial Risk if Skipped |
|---|---|---|
| Identify Type of PAD | Document atherosclerosis, claudication, ischemia. | Defaults to I73.9 unspecified. |
| Record Laterality & Location | Right vs left femoral, popliteal, or iliac artery. | Imaging or procedure denied. |
| Link to CPT Services | Pair I70.x/I73.9 with duplex scans, angioplasty, or wound care. | Claim denied for “not medically necessary.” |
| Prove Medical Necessity | Show failed conservative therapy before revascularization. | Angioplasty or bypass denied. |
| Capture Complications | Ulcers, gangrene, rest pain. | Wound care or bypass not reimbursed. |
| Submit with Supporting Evidence | Include imaging reports, wound photos, progress notes. | Delayed payment or audit recoupment. |
Compliance Risks with PAD Coding
Peripheral arterial disease (PAD) billing is highly scrutinized because it often leads to costly imaging, vascular interventions, wound care, and long-term disease management. The ICD-10 code for peripheral arterial disease (I73.9) is commonly misused, creating both reimbursement challenges and compliance exposure.
According to the Centers for Medicare & Medicaid Services (CMS), vascular disease is among the top conditions flagged in audits due to improper coding. The Office of Inspector General (OIG) has reported that many Medicare overpayments are tied to non-specific ICD-10 codes, missing complication documentation, or incorrect linkage between ICD-10 and CPT procedure codes.
The Healthcare Financial Management Association (HFMA) further notes that vascular claims coded with unspecified PAD codes like I73.9 face denial rates 30-40% higher than claims coded with specific I70.x atherosclerosis codes. These errors not only delay reimbursement but also increase audit risk.
| Compliance Risk | Impact on Billing & Compliance | Real-World Example | Prevention Strategy |
|---|---|---|---|
| Overuse of I73.9 (unspecified PAD) | Triggers denials and payer audits. | Duplex scan billed with I73.9 denied as “non-specific.” | Use I70.x codes with claudication, ulceration, or gangrene whenever documented. |
| Failure to Document Laterality & Location | Imaging/procedure claims denied due to incomplete detail. | Angioplasty billed without noting right vs left leg. | Always capture vessel (femoral, iliac, popliteal) + laterality in notes. |
| Missing Complications (ulcer, gangrene) | Leads to underpayment or claim rejection. | Wound care billed without linking ulcer to PAD. | Add complication codes (I70.23x, I70.26x) when documented. |
| Incorrect ICD-10/CPT Linkage | Claim denied as “not medically necessary.” | Angioplasty CPT 37225 paired with I73.9 unspecified. | Link specific I70.x code with procedure to show necessity. |
| Weak Documentation of Medical Necessity | High-cost procedures flagged as routine. | Bypass surgery denied because no failed conservative therapy documented. | Document failed medication/exercise therapy before invasive procedures. |
| Ignoring Local Coverage Determinations (LCDs/NCDs) | Denial despite correct coding. | Medicare denies imaging billed without LCD-supported diagnosis. | Cross-check payer LCD/NCD before claim submission. |
Did You Know? The American Heart Association (AHA) estimates that PAD patients cost the U.S. healthcare system $21 billion annually, making vascular claims a major target for payer scrutiny. Unspecified coding not only risks denials but also flags practices for utilization review and audits.
Why Should Providers Partner With PROMBS for PAD Billing?
Peripheral Artery Disease (PAD) billing is uniquely challenging because it requires precise ICD-10 coding for ischemia, ulceration, and gangrene, as well as exact CPT pairing for diagnostic imaging, angioplasty, bypass procedures, or wound care. Even a minor mismatch between the diagnosis and the billed service can trigger costly denials or audits. At PROMBS, our team ensures providers don’t just meet payer requirements, we position their claims to succeed under the strictest compliance scrutiny.
