Most are cutting out pass-through billing, so no. They'll say that they paid another provider already, and some are going back and taking recoupments, with our providers. If it's a CLIA-waived lab, though, you can still bill it most of the time. There's a lot of those - just Google it and you'll find the list from CMS.
The only time we really use to 90 mod is on paps, specifically for Aetna, because they require it, since ours are read elsewhere. You could also bill Q0091 for pap collection, or try to bill for specimen handling (99000) for other samples that you take, but those rarely pay separately with commercial payers.
