an ethical problem

If you could find some medical aid resources in your state for him via the internet that might help. I simply googled "uninsured medical treatment" and got useful hits, though I doubt they would provide sleep apnea screening and treatment. He probably has other health issues that need attention.

There are listings for older used CPAP machines on Craig's list in my area for $95 (google Craigs list and your city and state); I got mine used for $250 and it's a PR System One APAP with a mask. Programming it for the correct pressure would be tricky unless it was an auto. He could make it happen if he is committed and has not succumbed to the depression that sleep apnea can cause. As we all know, judgment and realizing available options can be very difficult with this untreated condition. At least he is still showing up for work so there is still hope. Not much you can do but offer suggestions and wish him the best. Since you have not witnessed a dangerous impairment you don't have a right to bring it up to his employer, and he might have legal rights against you if you did.

At this point I think you have done about all you can do.

The next step is an action step and you can't do that for him. He has to take the next step.

You can ask questions each time you see him and ask him if he has made the effort to have a sleep study done.

Now, if he answers that he tried but was beaten down by the system, or a lack of funds, then that opens up a whole new discussion.

I know that sleep doctors and DME supplies have "loaner" equipment, I am just not sure what criteria they use to lend it out.

I don't think Medicaid is an option. At least in my state, you can only get it if you are pregnant or disabled.

If he has tried a mask, he has already been diagnosed with apnea. If he actually wanted treatment, any doctor or dentist can write the script. He then could buy online, at the auction site or from craigs list. He would need to buy a an APAP machine as he does not know what the correct pressure setting is now. (He might know what the pressure was years ago, but I would contend that he can not know what pressure he needs now, without a $leep study or an Autopap.)