Paul Caruso had a 70th birthday plan—he was going to visit the United States with some friends, and celebrate it in Sin City. He purchased visitors health insurance through the Immigrant Secure plan and pored over the benefits so many times that he had the benefits by heart.

Just a couple of days after his big bash in Las Vegas, he was in an accident and broke a bone. He was, however, already calculating how much he’d have to spend out of his pocket. When he was presented with the bill, though, he thought he was being overcharged. What happened?

Most insurance plans with separate rates for different ages, prorate the benefits based on the age of the insured when the treatment occurs. In Paul’s case, since he reached age 70 after purchasing the plan, his deductible, which might have been $0, $50, or $100 up to age 70, automatically got set to $200 once he reached the golden age of 70.

When choosing a plan, however, you will not be allowed to purchase a plan unless the plan can be valid for the entire duration of coverage. In the Immigrant Secure plan, there are four maximum benefit levels, with those over 70 being eligible for two of them—the $10,000 maximum benefit level and the $50,000 maximum benefit level.