Ever been to your doctor and asked for your lab results and they aren't in your chart? This is because while most office run on some type of EMR (Electronic Medical Record), those EMR's don't connect with one another. So if you had labs done at your PCP (Primary Care Physicians) office and didn't ask them to forward them to your Cardiologist, Endocrinologist, Hematologist, etc. The only person seeing the blood work will be your PCP.
If you have blood work done at a lab such as Quest Diagnostic or a Beaumont Lab these labs will get mailed or faxed to ONLY the ordering physician. If any of your physicians have access to EPIC, (The EMR that Beaumont uses) then they will be able to access your records. Unfortunately Quest labs don't have don't have a system physician's can access from their offices, so the only way a specific physician will get your results is if you tell Quest where to send them.
In review, Labs taken at:
Physicians office: Ask them to send labs to every physician office you think may need or want them
Quest Diagnostic: Ask them to send labs to every physician office you think may need or want them
Beaumont Lab: Ask them to send labs to every physician office you think may need or want them (Just to be certain)