DEBUNKED: Non-Maskers Not Protected by Constitution, HIPAA
According to this story from USA Today, non-maskers in areas in which government officials have enacted a mask ordinance are NOT protected by the Constitution or HIPAA from being asked to prove they don't have to wear a mask.
The photo above (and others similar to it) has been circulating on Facebook since municipalities have begun to enact mask mandates. The claim is that, due to HIPAA regulations, the business can't ask you why you aren't wearing a mask if the reason is related to your health. It also claims that the 4th Amendment (Search & Seizure, etc) and 5th Amendment (Due Process, Self-Incrimination, etc) would protect you because it would be illegal for the business owner to FORCE you to show proof of your medical condition.
USA Today provides its sources that debunk the photo in question. As it turns out, HIPAA only provides protection from "covered entities": there is no law against me telling anyone of your medical condition(s) if you were to disclose those conditions to me. HIPAA makes it illegal for a medical facility (or other "covered entity") from disclosing your conditions if I were to ask them about your issues. But if you tell me your medical conditions, there are no laws preventing me from telling others.
As for the 4th and 5th Amendments, those are in place to protect you from the government, not private entities. If you enter a business during a mask mandate maskless, the business owner not only has the right to ask why you are not masked, but they also have the right to 1) alter service (ask you to wait outside for service, use delivery, etc) and/or 2) refuse service altogether.
I have to say that reading this article cleared up a lot of the questions I had about the issue. But considering the litigious nature of our State, I would guess that we'll be seeing lawsuits over this issue in the near future.