We have a lab that does drug testing for pain management patients. The lab work includes screening and then quantitative confirmation. One carrier will always allow only 1 unit of 82145 to be billed per day. They have indicated that regardless of how you bill the other units, 82145x2, 82145 and separate line 82145-59, or 82145-91, that only one unit is allowed per day. When speaking to them directly they have indicted that their logic is based on the MUE being one for this code. They also stated that because the testing is done using the same blood sample, that modifier 59 is not supported, and 91 is not applicable. Our documentation notes we have positive screen and then separate quantification of amphetamine and MDMA with findings. Is this correct, that 82145 and 82145-59 is incorrect and only 1 unit for this code is reimbursed????