Every time my wife's parents travel to the US we get them insurance. Their most recent visit was the first time we actually needed to use it, and it was just minor.

After they arrived they both quickly got sick, not flu type symptoms but a weird spot on the neck, dizziness, and a couple other things I can't remember. It seemed like it could be serious so we took them in. Doctor examined them, said they were okay and we went home. Filed a claim with insurance.

Insurance asked for medical history. They literally don't have any, nor was it really relevant as they weren't diagnosed with anything. I think the insurance wanted to claim pre-existing conditions (which they don't cover). They still refused to pay anything. The bill wasn't even that much, maybe a few hundred dollars? It was less than what I paid the insurance!