I work at a dermatopathology laboratory. When we receive slides from another facility/doctor's office for a second opinion and there are multiple specimens submitted (ie- Slide A from the back, Slide B from the nose) is it correct to bill for each specimen (88321 & 88321 w/ 76 mod) or can we only bill as one unit regardless of the number of specimens? I have worked there for 8 years and we have always billed out each specimen, however, another facility is telling us that these are being billed incorrectly and should only get one 88321 charge per patient. We have poured over our CPT book and cannot find documentation either way. If anyone can help me with this it would be greatly appreciated.