If it were me, it would depend on how it was documented. If the provider wanted to bill for time, then he would have documented the time he started and the time he finished and that would be translated to the appropriate E&M code (office visit). A provider that simply documents he spent 30 minutes with the parent is useless and you cannot bill for time, and you would simply code the visit with the correct E&M code from HPI, PFSH, Phys Exam, Level of Risk, etc. and the 30 min spent with the parent would then simply count as a historian for the patient. This is all according to the guidelines, I know b/c I've this same issue many times.