CRA finds that out-sourcing of laboratory diagnostic services causes them to cease to be GST/HST exempt

Laboratory, radiological or other diagnostic services provided by a health care facility on the order of a medical practitioner generally are exempt from HST or GST.  CRA considers that "services supplied by...independent contractors to the medical laboratory are not exempt under this provision," as such services are regarded as mere inputs to the diagnostic services provided by the laboratory, rather than being diagnostic services in their own right.

Neal Armstrong.  Summary of Excise and GST/HST News No. 87 under Health Care Services (GST/HST) Regulations, s. 2.