The regulations at 42 CFR 11.24(a) require that, for an applicable clinical trial for which registration information is required to be submitted, the registration information specified in section 402(j)(2)(A)(ii) of the PHS Act or 42 CFR 11.28(a) must be submitted within 21 days after the first human subject is enrolled. The final rule in 42 CFR 11.10(a) defines "enroll or enrolled" to mean a "human subject's, or their legally authorized representative's, agreement to participate in a clinical trial following completion of the informed consent process, as required in 21 CFR part 50 and/or 45 CFR part 46, as applicable." The definition further states that "for the purposes of ... [42 CFR part 11], potential subjects who are screened for the purpose of determining eligibility for a trial, but do not participate in the trial, are not considered enrolled, unless otherwise specified by the protocol."

For an applicable device clinical trial that is a pediatric postmarket surveillance of a device product and is not a clinical trial, the registration information specified in section 402(j)(2)(A)(ii) of the PHS Act or 42 CFR 11.28(b) must be submitted within 21 days after FDA approves the postmarket surveillance plan.