Many comments made regarding support of this measure do not consider the strengths/weaknesses and limitations of currently published literature that does not support masking.  Further significant literature is available in support of masking, particularly of those individuals who are or may be carrying sufficient viral load to transmit SARS-CoV-2, the virus that causes COVID-19.  

Please consider this article published in February: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0264389

Furthermore, studies recently cited in the comments, are not necessarily applicable based on location and significant ambiguity in regard to population, types of mask, actual compliance with proper mask-wearing, etc.  There are significant limitations of these studies.  

Regarding the comment of denial of care for "thousands upon thousands" of individuals.  This is likely grossly false.  Particularly considering the availability of telehealth visits for those who prefer not to wear a mask in office.  I personally have treated many patients who have not chosen to be vaccinated.  Several of these were patients with TMJD who meet this category, in a private room, them without a mask.  In these cases, I have done my best to mitigate my own potential risk, as these patients themselves were more carefree regarding exposure and mitigation.  I made a decision to not deny care to these patients, as I did personally feel that a denial of care, in this case, would not be ethical.  However, this certainly put me at greater risk.  As an individual with significant asthma, this was concerning.  Additionally, as a provider of care to other individuals at high risk, it is concerning to me that I could then put those patients at an increased risk to attend therapy. One individual's decision to not mask could potentially, and would likely, infringe upon another's right to health care in a safe environment.  

A strict, and legally punishable rule, in this case, would be grossly inappropriate, and frankly invalidating and unsupportive to the Physical Therapy profession, and individual integrity.  If one individual or practice is uncomfortable with having patients unmasked, for the sake of other patients' and therapists' health they should not be forced to see these patients.  Again, effects on access to care for individuals who prefer not to mask should be minimal if telehealth care is offered, which has been proven to be effective, or a patient seeks care elsewhere.  If so many places are open to unmasking this would not be a barrier to care as argued by prior commenters. And if there are significant enough places continuing to require masks as to limit care, then certainly the public opinion in this case would support continued masking.