Eligibility for a clinical trial isn't a single fixed checklist — it depends on the specific trial protocol you're being considered for, your diagnosis, your medical history, and criteria set by that trial's research team. For the exact age ranges and inclusion/exclusion categories across our current studies, see our eligibility criteria guide. This page focuses on how the eligibility process itself works, and answers the questions we hear most often from prospective participants — including those coordinating from outside the United States.

Common Eligibility Questions

I have more than one respiratory condition — can I still be considered?

Possibly. Trials are generally structured around a primary condition, but having a secondary or related condition doesn't automatically exclude you. This is exactly what the screening process is designed to sort out — raise your full medical history early so the study team can assess fit accurately.

Do I need a referral from my doctor to apply?

International candidates can generally self-refer to start the conversation, but you will need documentation confirming your diagnosis (such as prior test results, physician notes, or medical records) as part of screening. Bringing your treating physician into the process early tends to make this faster.

What happens after I think I might be eligible?

The next step is an initial screening conversation, where our team reviews your medical history and the specific trial's inclusion/exclusion criteria together with you. This is a conversation, not a commitment — you can ask questions and decide whether to proceed at every stage. Our eligibility criteria guide walks through the full three-step screening process, from phone pre-screening to in-person evaluation.

Is there a cost to find out if I'm eligible?

No. There is no cost or obligation for the initial screening conversation. All study-related medical care during a trial — including doctor visits, laboratory tests, lung function testing, and investigational medications — is also provided at no cost to you. Financial compensation for time and travel is available separately; see our compensation explainer.

For a full walkthrough of what happens from first contact through study completion, see our participant guide. Still deciding whether a trial makes sense for you at all? Our guide on Is a Clinical Trial Right for Me? can help. If you're coordinating from outside the United States, our FAQ for International Participants covers visas, travel, and working with a physician who isn't local. For general questions not covered here, visit our full Clinical Trials FAQ.

Important Disclosures

This page is provided for general informational purposes to help prospective participants think through their decision and does not constitute medical advice. All studies are reviewed and approved by an independent Institutional Review Board (IRB) and are conducted in compliance with ICH-GCP (Good Clinical Practice) guidelines and applicable FDA regulations. Clinical trials are investigational research studies; participation does not guarantee any therapeutic benefit. Participation is completely voluntary. Please consult your physician to determine whether a clinical trial may be appropriate for your individual situation.