Your facility really should be the one to give you direction on this. Where I work, the facility requires this, but we are coding both the professional and facility charges, so the situation may be different from yours. Resident services do have specific documentation requirements to show the involvement of the teaching physician - these have been revised recently to allow that the attestation be done by the residents in some cases, however many facilities still require the attestation be done and signed by the teaching physician. A PA service, on the other hand, does not require a co-signature or attestation solely for coding purposes, but the facility may want this in the documentation due to local state regulations or other compliance reasons. If you're coding just for the facility side, you may or may not be responsible for ensuring that the professional documentation includes these attestations or co-signatures, but your coding managers or supervisors should be the ones to let you know what their expectation is for this.