Neuropsychological testing 96118-96125

In the past, neuropsych testing has been considered a "global" service, not able to be billed as both professional and facility charges when billing as a Hospital Outpatient Department. There are now APCs for testing codes, and I'd like to know if others are billing both components, and with what success. If you are getting paid for the facility fee by Medicare via the APC, is your reimbursement based on # of hours spent testing, or is it a flat payment?

Also, one of our large carriers wants us to use AH on all of those codes as a discipline modifier, even for the codes which don't call for a PhD psychologist, such as 96119.