A friend of mines wife needed a lot of dental treatment, she went to Mexico, forget the name of the place but south of Cancun, a lot cheaper than the US and she got a holiday thrown in and the facilities and treatment were excellent.
I am in Colorado and have heard of people going to the School of Dentistry in Denver for cheaper more local cover.
Most common situation for health cover is to get added to their Spouses arrangements.
I have come across a couple of cases where people have had the I 693 covered by Medical Insurance, seems very rare and always wondered if this was a mistake by the Insurer.