Interventional Radiology Residency and Fellowship

Interventional radiology (IR) training in the United States has undergone a fundamental restructuring since the Accreditation Council for Graduate Medical Education (ACGME) established the integrated interventional radiology residency as a distinct specialty pathway in 2016. This page covers the two primary training structures — the integrated IR residency and the traditional fellowship route — their regulatory frameworks, program requirements, and the clinical and procedural scopes each pathway produces. Understanding these pathways matters because the credentialing structure directly governs which procedures an IR physician is authorized to perform and how hospital privileging committees evaluate applicants.

For a broader orientation to the specialty landscape, the Radiology Authority home provides context on the full range of imaging and procedural disciplines covered across this reference network.

Definition and scope

Interventional radiology is the branch of medicine in which physicians use image guidance — including fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging — to perform minimally invasive diagnostic and therapeutic procedures. Training pathways leading to IR certification fall into two ACGME-recognized structures:

Integrated IR Residency (IR/DR) — A six-year program beginning after medical school, combining diagnostic radiology training with dedicated IR clinical rotations. Graduates are eligible for dual certification in both Diagnostic Radiology and Interventional Radiology through the American Board of Radiology (ABR).
Independent IR Residency — A two-year program open to physicians who have already completed an ACGME-accredited diagnostic radiology residency (typically four years post-internship). This pathway was introduced as a bridge route and is approved through at least 2024 (ACGME Program Requirements for Graduate Medical Education in Interventional Radiology).

Prior to 2016, IR training existed exclusively as a one-year fellowship appended to diagnostic radiology residency. The Society of Interventional Radiology (SIR) and the ABR jointly advocated for specialty status, and the ACGME granted IR its own program code: 4229 for integrated programs and 4233 for independent programs.

The regulatory and credentialing context for radiology practice — including how hospital privileging intersects with board certification — is detailed in the regulatory context for radiology reference page.

How it works

Integrated IR Residency (IR/DR) — six-year structure:

Year 1 — Internship/Transitional Year: Candidates match into a clinical internship (medicine, surgery, or transitional), which is incorporated within the six-year count at integrated programs. ACGME requires 12 months of broad clinical exposure.
Years 2–4 — Diagnostic Radiology Core: Three years of structured diagnostic radiology training covering all major modalities. Programs must meet ACGME Milestones 2.0 competency benchmarks in diagnostic interpretation.
Years 5–6 — IR Clinical Training: A minimum of 24 months of dedicated IR training. ACGME program requirements mandate exposure to vascular access, embolization, ablation, biliary intervention, venous thromboembolic disease management, and oncologic interventions (ACGME Program Requirements, Section IV.B).
Certification: Graduates sit for ABR qualifying (written) and certifying (oral) examinations in both Diagnostic Radiology and Interventional Radiology. Dual board certification requires passing both examination sets.

Independent IR Residency — two-year structure:

Physicians who completed diagnostic radiology residency prior to or during the transition period may enter a two-year independent IR program. These 24 months replicate the clinical IR content of years 5–6 in integrated programs. As of the ACGME's 2022 review cycle, 79 independent IR residency programs were accredited in the United States (ACGME Data Resource Book, Academic Year 2022-2023).

Fellowship (pre-2016 legacy context):

Before the specialty restructuring, a one-year Vascular and Interventional Radiology (VIR) fellowship served as the sole pathway. Physicians who trained under the fellowship model and hold ABR subspecialty certification in VIR remain credentialed; however, the ACGME no longer accredits new VIR fellowship programs as a standalone entry pathway to IR certification. Comparable fellowship structures persist for downstream subspecialization — see neuroradiology fellowship and body imaging fellowship for parallel structures in other subspecialties.

Common scenarios

Procedural scope in training:

ACGME minimum case log requirements specify that integrated and independent IR residents must perform a defined volume across 14 procedural categories before program completion. Key minimums established in the 2020 program requirements revision include:

100 vascular access procedures (central venous, arterial)
50 arterial interventions (angioplasty, stent placement, thrombolysis)
50 venous interventions (thrombus management, venous sampling)
30 embolization procedures (tumor, hemorrhage, uterine fibroid)
25 ablation procedures (radiofrequency, microwave, or cryoablation)
25 biliary or urinary drainage procedures

Trainees develop proficiency in procedures such as angiography and vascular interventions, image-guided biopsy, embolization, catheter drainage for abscess, radiofrequency ablation, stent placement, and uterine fibroid embolization.

Radiation safety obligations in training:

Because IR procedures involve fluoroscopic imaging, residents accumulate occupational radiation exposure subject to Nuclear Regulatory Commission (NRC) dose limits of 50 millisieverts (mSv) per year whole-body exposure and 150 mSv per year for the lens of the eye (NRC 10 CFR Part 20). Programs operating under ACGME oversight must document radiation safety training under the requirements of the Joint Commission and institutional radiation safety committees.

Decision boundaries

Integrated vs. independent pathway — key distinctions:

Dimension	Integrated IR/DR	Independent IR
Entry point	After medical school (PGY-1)	After DR residency completion
Total training duration	6 years	DR (4–5 years) + 2 years IR
Board outcomes	Dual ABR certification (DR + IR)	IR certification only (DR already held)
Match mechanism	NRMP Main Residency Match	NRMP Supplemental Offer and Acceptance Program (SOAP) or direct program arrangement
ACGME program code	4229	4233

Specialty overlap with vascular surgery:

IR and vascular surgery share procedural territory in endovascular intervention. The American Board of Surgery and the American Board of Radiology each certify physicians to perform endovascular procedures; hospital privileging committees evaluate candidates under institutional criteria that may differ from board certification scope. SIR and the Society for Vascular Surgery have published joint statements on procedural overlap, but no federal statute defines exclusive procedural jurisdiction between the two specialties.

Subspecialty fellowship after IR residency:

Completing an IR residency does not preclude additional subspecialty training. Physicians may pursue a dedicated year of advanced training in areas such as interventional oncology, pediatric IR, or neurointerventional surgery. These post-residency fellowships are not currently governed by ACGME accreditation standards in all cases; some are offered under the Society of Interventional Radiology's formal interventional radiology fellowship framework.

The path to IR begins with undergraduate and medical school prerequisites documented in the becoming a radiologist reference, and board examination structure is detailed in diagnostic radiology board certification.

References

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