(July 8, 2026): Since 2023, ProPublica[1] has conducted a broad investigation into the extraordinarily high number of peripheral vascular procedures performed in office-based laboratories (OBLs) rather than hospital outpatient departments around the country. Over the last three years, the organization has published at least fourteen articles examining the medical necessity and over-utilization of these procedures.[2] From its investigation, ProPublica has unsurprisingly shifted Congressional attention to the matter, alleging that the overuse of office-based vascular procedures has fueled a surge of interventions that placed patients at risk of amputation or death. In this article, we examine the current enforcement environment and its focus on health care providers performing office-based peripheral vascular procedures. We also review how a health care provider should respond if its utilization, coding, or billing practices are investigated by the government.
I. Overview of Office-Based Peripheral Vascular Procedures:
The term “peripheral vascular procedure” refers to a broad range of minimally invasive, catheter-based interventions that are performed on a patient’s blood vessels (arteries or veins). Peripheral vascular procedures can prevent limb loss, reduce cardiovascular mortality, relieve disabling symptoms, sustain dialysis patients, and restore functional independence. As our nation’s Medicare population grows and the prevalence of diabetes and cardiovascular risk factors continues to rise, the importance of these procedures will only increase.
Over the last 30 years, the primary site in which practitioners render these services has gradually migrated from traditional hospital inpatient and outpatient departments to physician-owned, freestanding office-based clinical facilities.[3] The procedures performed in an office-based laboratory treat diseases of the peripheral vascular system (i.e., blood vessels outside the heart and brain) using endovascular techniques that do not require general anesthesia or large surgical incisions.[4] CMS program integrity contractors and law enforcement are currently focusing on office-based angioplasties,[5] stents,[6] tibial artery procedures,[7] and atherectomies.[8]
The shift of peripheral vascular procedures from hospitals to office-based laboratories accelerated significantly after the Deficit Reduction Act of 2005 [10] and subsequent Centers for Medicare and Medicaid Services (CMS) reimbursement changes in 2008, which increased payments for procedures performed in ambulatory settings.[11] In making these changes, CMS had two main goals: (1) to improve patient access and (2) to reduce overall healthcare costs. Not surprisingly, office-based peripheral vascular procedures grew dramatically. Moreover, the dramatic shift from inpatient to office-based peripheral vascular procedures showed a rise from 15% in 1990 to an estimated 65% as of 2025. Today, more than 1300 office-based peripheral vascular laboratories operate in the United States, and the number continues to grow.[12]
II. The OIG’s Regulatory Concerns Regarding Peripheral Vascular Procedures:
The Office of Inspector General (OIG) recently issued a report framing the agency’s concerns regarding the billing of office-based peripheral vascular procedures. [13] The report notes that Medicare Part B paid over $1 billion in 2022 for peripheral vascular procedures intended to relieve leg pain caused by arterial narrowing or blockage.[14] The OIG found that from 2019 through 2023, physicians increasingly shifted peripheral vascular procedures from hospital outpatient departments to office-based laboratories. Moreover, the OIG noted that in 2023, physicians performed atherectomy and tibial artery procedures in office-based laboratories at high rates, despite controversy surrounding the routine use of these interventions. While the OIG’s findings do not establish fraud, they will undoubtedly be used to justify focused administrative claims audits, targeted data analyses, and administrative recoupment actions. The OIG concluded its report by recommending that CMS monitor office-based peripheral vascular billing to identify any medically unnecessary procedures and recommended that CMS follow up with office-based practices and billing physicians whose billing practices may be improper. This sets a precedent for heightened enforcement efforts in the coming months, perhaps years.
III. Highest-Risk Peripheral Vascular Procedures
CMS’s efforts to improve patient access and reduce costs by encouraging peripheral vascular procedures in outpatient and office-based settings shifted the market toward office-based settings and led to significant increases in utilization that now raise concerns about program integrity. Three main factors create high enforcement risk regarding these procedures: (1) high utilization, (2) high reimbursement, and (3) substantial medical-necessity judgment. The migration of these procedures to office-based settings has drawn significant scrutiny from CMS, its program integrity contractors, the OIG, and the Department of Justice (DOJ).
Recent enforcement efforts focus less on a single billing technicality and more on a cluster of procedure groups commonly billed for lower-extremity arterial interventions. Although coding specifics turn on the exact procedure performed, the government’s office-based laboratory peripheral vascular enforcement efforts have centered on the following categories.
A. Common Lower-Extremity Revascularization Code Groups.
The principal CPT codes typically implicated in CMS contractor audits and law enforcement investigations include:
| Procedure Groups | Illustrative CPT Codes and Areas of Interest to Auditors | Typical Questions Raised by Auditors |
|---|---|---|
| Endovascular revascularization of the iliac artery. | CPT lower-extremity endovascular revascularization codes:
|
Does the provider’s documentation support the treated vessel, lesion, modality, and separate-vessel billing? |
| Endovascular revascularization, femoral/popliteal artery. | CPT lower-extremity revascularization codes include:
|
Is there any evidence of overuse of atherectomy, repeat procedures, or vessel-count inflation?
Does the record explain why atherectomy, as opposed to angioplasty alone, was reasonable and necessary for the specific lesion and patient presentation? |
| Endovascular revascularization, tibial/peroneal artery | CPT lower-extremity tibial/peroneal intervention codes include:
|
Was it appropriate to treat below-the-knee disease in patients with mild symptoms or poor documentation of limb-threatening ischemia?
Was the patient’s clinical condition severe enough and sufficiently documented to justify tibial intervention? |
| Diagnostic angiography. | Lower-extremity angiography and catheterization codes.
|
Did the provider improperly unbundle diagnostic studies from intervention when the diagnostic service was not separately billable? |
| Intravascular imaging and adjunct services. | Ultrasound and other add-on imaging guidance codes. | Did the provider improperly bill for add-on services without adequate support for medical necessity or performance? |
| Office-based ancillary billing. | Supplies, radiology supervision/interpretation, and related professional components where applicable | Does it appear that procedures were performed in an effort to maximize site-of-service revenues?
Were ancillary charges billed to Medicare supported by the documentation? |
Both CMS contractors and law enforcement have shown significant interest in health care provider claims for atherectomies, angioplasties, stent placements, tibial artery interventions, and repeat bilateral lower-extremity procedures performed in office-based settings.
B. High-Risk Enforcement Factors
These CPT codes have drawn considerable scrutiny from CMS program integrity contractors and law enforcement for several reasons. First, the OIG has documented substantial physician Part B payments tied to peripheral vascular procedures performed in office settings. This high concentration and rapid acceleration in payments to physician-owned peripheral vascular laboratories have put these claims at higher risk of investigative and punitive audits. In recent peripheral vascular cases, DOJ has alleged that the procedures performed have involved serial, repetitive interventions at short intervals, often bilateral, even though a patient’s symptoms or the imaging studies did not support the frequency or scope of the procedures conducted. The OIG has expressed concerns about the routine use of atherectomies due to inherent risks of complications and potential poor outcomes.
Additionally, physicians may occasionally overstate or understate the justification for medical necessity in documentation, leading auditors to struggle to verify that encounter notes are sufficient. For example, the distinction between vascular claudication[15] that can be managed conservatively in a patient and symptoms warranting invasive intervention can be fact-intensive and is vulnerable to understatement in documentation.
Further, coding lower-extremity intervention procedures can be complicated, and the documentation supporting these procedures is often incomplete. To support medical necessity, a health care provider must fully document a patient’s vascular condition, note the number of treated vessels, laterality, lesion crossing, and whether diagnostic imaging was separately reportable. The more complex the coding architecture, the more fertile the ground for overpayment allegations.
Finally, the OIG has noted that the routine use of tibial artery procedures is controversial and that their medical necessity is often questionable.
C. Common Documentation Insufficiencies.
When CMS program integrity contractors and law enforcement auditors have examined peripheral vascular procedure documentation, these reviewers have typically focused on the following issues when examining a patient’s medical records:
- What were the patient’s presenting symptoms and the severity of those symptoms?
- Is there evidence of prior conservative therapy, including exercise and medical management, first being tried?
- Are there objective diagnostic findings that correlate to the patient’s documented symptoms;
- What were the precise anatomic vessel(s) treated?
- Was there hemodynamically significant stenosis?
- Why was treatment necessary in both legs or in multiple vessels?
- Why was an atherectomy, rather than a less intensive modality, selected?
- Were the separately billed diagnostic angiography procedures truly distinct and necessary?
- Did repeat interventions reflect restenosis, progression, or was it unnecessary serial treatment?
D. Audits by Medicare Administrative Contractors (MACs).
Medicare Administrative Contractors (MACs) process Medicare Part B claims and conduct medical reviews. They are typically the first entities to identify aberrant billing trends through claims analytics, prepayment reviews, targeted probe-and-educate initiatives, and post-payment audits. With respect to office-based peripheral vascular procedures, MACs are likely to examine:
- Unusually high utilization of atherectomy or tibial interventions.
- Frequent bilateral procedures.
- Repeated interventions on the same beneficiary.
- High per-beneficiary payments.
- Utilization patterns that diverge sharply from specialty peers.
- Insufficiently documented diagnostic angiography billed with intervention.
It is important to remember that claim denials and overpayment findings by a MAC can lead to broader audits and/or law enforcement investigations.
E. Unified Program Integrity Contractors (UPICs).
Unified Program Integrity Contractors (UPICs) investigate potential fraud, waste, and abuse in Medicare and Medicaid. Where claims patterns suggest systemic medically unnecessary procedures or abusive referral relationships, UPICs may escalate the matter to CMS, the OIG, or DOJ. The OIG’s 2026 recommendation that CMS “monitor billing to identify peripheral vascular procedures that may be medically unnecessary” aligns closely with the data-driven surveillance that UPICs and related program integrity entities perform.[16]
F. Supplemental Medical Review Contractors (SMRCs) and other CMS Audit Contractors.
Depending on the program and claim type, Supplemental Medicare Review Contractors (SMRCs) may be assigned to conduct specialized medical review or data analysis. Although the nomenclature can vary over time and by CMS initiative, the practical takeaway is that office-based peripheral vascular providers should expect overlapping review channels rather than a single-auditor model.
G. Recovery Audit Contractors (RACs).
When coding or payment errors result in overpayments, Recovery Audit Contractors (RACs) may also become involved, especially if a straightforward payment issue can be identified. Although Recovery Auditor activity is often associated with inpatient and facility claims, physician office claims can also be affected, depending on CMS review priorities.
IV. Common DOJ and OIG Enforcement Theories:
A. Medical Necessity Under the False Claims Act.[17]
The government’s primary civil theory in recent office-based vascular matters has been that providers billed Medicare for medically unnecessary peripheral vascular procedures. The False Claims Act imposes liability on any person who knowingly presents, or causes to be presented, a false or fraudulent claim for payment to the United States or knowingly makes or uses a false record material to such a claim.[18]. In medically unnecessary procedure cases, falsity often depends on allegations that the provider:
- Overstated symptoms.
- Documented stenosis that was more severe than the imaging studies showed.
- Conducted peripheral vascular procedures on patients where the disease was mild or absent.
- Performed peripheral vascular procedures in asymptomatic or minimally symptomatic limbs.
- Repeated peripheral vascular procedures without evidence of a clinical indication for the intervention.
- Created charting that masked the lack of medical necessity.
- Documented symptoms or procedures not actually observed or rendered.
As an example, in May 2026, the DOJ announced a False Claims Act settlement with a California-based vascular practice that was alleged to have submitted false claims for medically unnecessary vascular interventional procedures. The DOJ alleged that the practice and the rendering physician submitted false claims for medically unnecessary dialysis access interventions, including angioplasty and stent procedures. To resolve the False Claims Act allegations, the defendants agreed to pay more than $6.7 million.[19]
B. Kickbacks[20] and Financial Relationships.
A second enforcement theory is the use of financial arrangements to induce referrals for office-based peripheral vascular procedures. For example, several years ago, multiple whistleblower cases were filed in the District of Arizona against a nationwide chain of outpatient vascular clinics, alleging that the clinic chain and its founder improperly allocated clinic equity to referring physicians based on their referral volume, in violation of the federal Anti-Kickback Statute. The DOJ considered the equity allocations to be improper inducements. CMS subsequently suspended the company’s Medicare payments, and the defendant chain was forced to file for bankruptcy.[21]
C. False Documentation and Upcoding.
When pursuing peripheral vascular cases, the government also alleges that the office-based procedures performed involved false documentation, inflated symptom severity, and/or coding these claims beyond what the operative note supports. In one recent case, the DOJ alleged “false documentation of symptoms” in support of its case against the organization. In practice, coding-based allegations may be pursued administratively as overpayments, civilly under the False Claims Act, or both, depending on proof of knowledge and materiality.[22]
V. Practical Red Flags for Counsel and Compliance Officers:
The following chart summarizes many of the red flags that can trigger an audit or investigation by the OIG and the DOJ:
| Red flag | Law Enforcement Action |
|---|---|
| Extremely high atherectomy utilization. | The OIG specifically identified atherectomy as controversial and frequently used in office-based laboratories. |
| High volume of tibial interventions. | The OIG identified tibial procedures as controversial and commonly used. |
| Concentrated billing by a small number of physicians. | The OIG found that a small number of physicians accounted for 61% of the agency's identified alleged improper payments. |
| Repeated bilateral procedures at short intervals. | The DOJ alleged repeated bilateral peripheral artery disease interventions despite limited symptoms. |
| Treatment of mild or no stenosis. | This allegation is often central in cases where the DOJ alleges that the procedure conducted was not medically necessary. |
| Investor-referral relationships in office-based laboratories. | This was the primary allegation under the Anti-Kickback Statute in the District of Arizona case discussed above. |
| Pressure on employed physicians to increase the number of peripheral vascular procedures. | Supports overutilization and intent theories. |
| Large OBL revenue shift from hospital settings. | OIG identified migration to OBLs as an important utilization trend. |
VI. Conclusion:
Office-based peripheral vascular providers and their rendering physicians need to ensure that these procedures meet all applicable medical-necessity requirements. It is also essential that each patient’s clinical condition and disease severity are fully and accurately documented. Practices and rendering providers must also confirm that their coding and billing practices are compliant with the payor’s requirements. Finally, practices and affiliated providers must exercise caution when entering any business arrangement. The Anti-Kickback Statute is quite broad, and violations can lead to significant criminal liability. Are your office-based peripheral vascular procedures under audit or investigation? If so, we recommend that you engage experienced health law counsel to represent you.
- [1] ProPublica is an independent, non-profit investigative organization based in New York City, NY. It was first established in 2007 and has a team of more than 150 investigative journalists. Its mission is: “To expose abuses of power and betrayals of the public trust by government, business, and other institutions, using the moral force of investigative journalism to spur reform through the sustained spotlighting of wrongdoing.”
- [2] Several of the articles have raised serious concerns regarding questionable medical necessity and improper business practices. These articles include: (1) “Steak Dinners, Sales Reps and Risky Procedures: Inside the Big Business of Clogged Arteries,” (February 16, 2023); (2) “In the “Wild West” of Outpatient Vascular Care, Doctors Can Reap Huge Payments as Patients Risk Life and Limb, (May 24, 2023); and (3) “Thousands of Patients May Be Undergoing Vascular Procedures Too Soon or Unnecessarily,” (December 12, 2023).
- [3] Krishna Jain, Running a Quality-Focused Office-Based Laboratory, 2 JVS-Vascular Insights 100076 (2024). https://doi.org/10.1016/j.jvsvi.2024.100076.
- [4] Vascular Institute of Michigan, Office-Based Lab (OBL) https://vascularim.com/obl/.
- [5] An angioplasty is a minimally invasive procedure used to open blocked or narrowed arteries, restoring normal blood flow. It is most commonly performed on coronary arteries, but it can also be used to treat arteries in the legs, arms, or kidneys. See National Coverage Determination (NCD) 20.7 and related active Local Coverage Determinations (LCDs).
- [6] A peripheral vascular stent procedure is a minimally invasive treatment used to open narrowed or blocked arteries outside the heart. It improves blood flow to the limbs, kidneys, or brain by inserting a small, expandable metal mesh tube into the vessel to keep it open and prevent collapse. Reference LCDs L38231, L37893, and L35998 to determine if your jurisdiction’s administrative contractor has published related coverage guidance.
- [7] The OIG has noted that there is significant controversy surrounding the routine tibial artery procedures and noted substantial office-based utilization. Below-the-knee interventions can raise acute necessity concerns where documentation does not support chronic limb-threatening ischemia, tissue loss, rest pain, or other indications proportionate to the intervention. There are no active NCDs of LCDs related to these procedures at this time.
- [8] Atherectomy procedures are at the center of law enforcement’s current scrutiny. The OIG has noted that the routine use of atherectomies in office-based laboratories is controversial due to potential complications and poor outcomes. Since an atherectomy may be reimbursed at higher levels than more conservative options, it predictably attracts comparative utilization analysis.
- [9] See the OIG’s 2026 report titled “Utilization Trends and Medicare Part B Billing for Office-Based Peripheral Vascular Procedures Raise Questions About Program Integrity.” Page 2 (OEI-01-24-00250)(May 2026).
- [10] Deficit Reduction Act of 2005, Pub. Law 109-171 (February 8, 2006).
- [11] In 2007 and 2008, the Centers for Medicare & Medicaid Services (CMS) took several steps to increase reimbursement for procedures performed in ambulatory settings. The primary Final Rule impacting the viability of performing peripheral vascular procedures in an office setting was published in the Federal Register in November 2007. This Final Rule revised resource-based practice expense relative value units (RVUs) for the physician fee schedule. It effectively increased office-based practice expense RVUs for a range of procedures, including catheter-based vascular interventions, thereby making it financially advantageous for health care providers to perform these procedures in an office-based setting rather than in a hospital. See Final Rule “Medicare Program -- Revisions to Payment Policies Under the Physician Fee Schedule, and Other Part B Payment Policies for CY 2008,” Final Rule, 72 Fed. Reg. 66,222 (Nov. 27, 2007) https://www.federalregister.gov/documents/2007/11/27/07-5506/medicare-program-revisions-to-payment-policies-under-the-physician-fee-schedule-and-other-part-bIn addition to the main Final Rule discussed above, CMS also enacted changes to the ambulatory surgical center (ASC) payment system that indirectly made office-based peripheral vascular interventions more economically viable relative to inpatient, hospital-based procedures. See Final Rule “Medicare Program: Changes to the Hospital Outpatient Prospective Payment System and CY 2008 Payment Rates; Changes to the Ambulatory Surgical Center Payment System and CY 2008 Payment Rates.” 72 Fed. Reg. 66,580 (Nov. 27, 2007). https://www.federalregister.gov/documents/2007/11/27/07-5507/medicare-program-changes-to-the-hospital-outpatient-prospective-payment-system-and-cy-2008-payment.
Also see Final Rule “Medicare Program; Payment Policies Under the Physician Fee Schedule and Other Revisions to Part B for CY 2009.” 73 Fed. Reg. 69,726 (Nov. 19, 2008). https://www.federalregister.gov/documents/2008/11/19/E8-26213/medicare-program-payment-policies-under-the-physician-fee-schedule-and-other-revisions-to-part-b-for - [12] Aman Sinha, Austin Beahm, Peter Schultz, Anil Hingorani, Chantel Moore, Reva Bhushan, “Mapping the Evolving Landscape of Office-Based Labs in Vascular Surgery 2010–2023.” JVS-Vascular Insights (May 2026). https://www.sciencedirect.com/science/article/pii/S2949912726000905?__cf_chl_f_tk=R2RMlTR2JcviUyvyAcsOUcP9O_VDleEtgmkcLTp0ang-1782951540-1.0.1.1-biuayViuqpF2Q0cX3xXPq17zNlc45P7YI.kUPyf2B5Y
- [13] OIG, “Utilization Trends and Medicare Part B Billing for Office-Based Peripheral Vascular Procedures Raise Questions About Program Integrity.” (OEI-01-24-00250)(May 2026).
- [14] Ibid.
- [15] “Vascular Claudication” is a classic symptom of peripheral artery disease, in which narrowed or blocked arteries (due to plaque buildup) prevent sufficient oxygen-rich blood from reaching active muscles.
- [16] See note 13.
- [17] For a deeper dive into the False Claims Act, please see our article titled “False Claims Act Matters and Cases – An Overview.”
- [18] 31 U.S.C. §3729(a)(1)(A)-(B).
- [19] DOJ, “Vascular Practice and Physician Agree to Pay More Than $6.73M to Settle False Claims Act Allegations of Unnecessary Vascular Interventional Procedures,” (May 2026), retrieved at
https://www.justice.gov/opa/pr/vascular-practice-and-physician-agree-pay-more-673m-settle-false-claims-act-allegations - [20] An overview of the federal Anti-Kickback Statute is provided in our article titled “Anti-Kickback Statute Risk Issues for Health Care Providers and Suppliers.”
- [21] See U.S. ex rel. Radhakrishnan, et al. v. Gampel, et al., No. 20-CV-176, 2024 WL 894671 (D. Ariz. Mar. 1, 2024).
- [22] See note 17.