What minimum qualifications must an amateur radio operator hold to operate cross-band repeaters?

Operating (which means using or communicating through) a cross-band repeater only requires a Basic qualification. As long as the frequencies being used fall within the Basic operator's standard privileges (such as the VHF and UHF bands), no higher qualification is needed. It is vital to distinguish between installing a repeater and operating one. While installation legally demands the Advanced certificate, simply keying up your radio and talking through a cross-band repeater is permitted for any Basic operator.