Especially if they allow a medical exemption and now are back tracking on that. 

Going back to when you converted that property to rental, if you had to do that because you moved for a job or medical related reason then you may be able to get an amount of the gain tax free prorated by the months you lived there.  

I'm currently renting an apartment and my roommate is off to medical school this summer.

One of my rentals is in a college town that I rent to Medical students. 

I offered monthly pricing during the COVID-19 closings for monthly rentals to medical personnel. 

And if you haven't lived there for two years yet then you would have to qualify for one of the exclusions (job related transfer or medical situation, or unforeseen event). 

I know the news shows the cities desperate for medical personnel, but in many places the surge has not hit.

I will soon take up a Medical Laboratory Scientist travel job with the intent to fund more real-estate buying and achieve my ultimate goal of not having to trade time for money. 

Or is it a medical debt from a few years ago when their child got sick with cancer that they just haven't been able to keep up with and therefore has dragged down their credit?

I am in the medical field, so I am not as educated in the real estate area as you all.