FDA Early Feasibility Study (EFS) Program: The Complete Guide — bioaccess®

What is the FDA Early Feasibility Study program? The FDA Early Feasibility Study (EFS) program is the FDA's pathway for studying a medical device early in development in a small number of subjects — assessing initial clinical safety and device functionality while the design may still change. The path runs through a Pre-Submission (align on risk, testing, and mitigation with the FDA) to an IDE, with the agency targeting approval in the first 30-day review cycle. EFS is not the same thing as first-in-human: FIH marks first clinical use anywhere, while EFS is the FDA's mechanism for early, limited, iterative clinical evaluation. Official program page: FDA — Early Feasibility Studies.

Program figures (about 60 IDEs/year, 4,000+ participants) are as reported in the program's 10-year retrospective (Endovascular Today, May 2026). This page is general information, not regulatory advice.

What counts as an early feasibility study

The EFS path: from first contact to IDE

EFS by the numbers

Where sponsors get stuck

EFS 2.0 and multigeography studies

The FDA is moving toward "EFS 2.0" — a next phase shaped by ten years of experience — including recognition of the benefit of multigeography and global studies rather than insisting every early study run on U.S. soil.

U.S. EFS or Latin America FIH?

Primary sources

EFS in Latin America · FDA acceptance of OUS data · FIH CRO overview · Book a strategy call

Founder perspective

A MedTech founder's scarcest resources are time and runway. By anchoring the regulatory strategy in the U.S. and running the first-in-human study across Latin America, our clients reach human data meaningfully faster and at a lower per-patient cost than a U.S. or EU program — with GCP-compliant (ISO 14155) data quality supporting eligibility for FDA acceptance under 21 CFR 812.28. Individual timelines and costs vary and are not guaranteed.
— Julio G. Martinez-Clark, Co-Founder & CEO of bioaccess®, bioaccess®