I work for an independent laboratory, and recently we have been receiving numerous denials and requests for medical records. They are stating that we should not be billing POS 81 unless we are the ones collecting the specimen, otherwise we have to bill place of service according to where the specimen was obtained? I am completely confused by this because we are processing the specimen that has been sent to us by surgery centers or office visits, so i would assume we use 81(independent laboratory) not where the specimen was obtained. Please anyone having this issue? Any insight?