88305 and Modifier 90

I've heard that it is illegal to bill for 88305 if you use an outside lab(in California) with a 90 modifier. Is it?

maybe

It depends on California's rules on pass through billing. Some states clearly say this is not permitted; California is pretty progressive so I would think they have addressed this somewhere. Ask your medical society. But -90 is reported by labs when they outsource the test to another lab.