Sorry for the delay, I was away for the weekend and I had to look this one up.
It would seem fairly easy to bill for a pap smear, but it can be quite complicated. If it is a screening pap then you need to use the appropriate dx, V72.31 or V76.2 for low risk or V15.89 for high risk, and then Medicare requires the G0101 hcpcs code for screening paps. You can bill an E&M with the pap if there was a reason for the ov, but you should use the 25 modifier.
If it is a medical pap, then you would use the appropriate ICD diagnosis code and the appropriate medical pap code, 88141 & 88174 would work. Again you can bill the E&M with the pap.
Hope that helps
Michele