No they can't. It costs an obscene amount of money and insurance won't cover it unless you get a sleep study ($$$$$) and it proves you have sleep apnea. Don't have apnea but still snore? Tough luck!
My insurance paid for all of that without a quibble after my family doctor made a referral. My insurance company has many customers. So I am going to stick with "many people".
I got a sleep study on insurance(yes $$$). I talked to a sleep doctor on my Cigna insurance and bought directly on cpap.com without going through insurance for $400.