For an NSF SBIR phase I, I understand that 1/3 of the budget can be used for consultants and CROs (does this fall under subcontractors?).
In the case of CROs, the company needs to be US based. However, I am unclear about this definition given that many CROs in my field are international, and so while they have sites (perhaps even headquarters) in the US, they do work outside of the US as well.
Is there a more solid definition of what constitutes a US CRO for the purposes of a NSF SBIR?