[seanmcdirmid]

Don't forget babies. Child birth is expensive and the reason why young women had to pay more than young men pre-ACA.

Also, skipping your annual health check ups is bad for your insurance company in the long run, so this, at least, they have a huge incentive to make sure you go.

Most people are interested in health care and not health insurance, meaning, we know we are going to use the doctor for something...it isn't a big surprise when your wife gets pregnant (well...I mean...). It isn't a big surprise when you start breaking down toward the end of your life, which is why ~40% of our health care is already socialized via Medicare.

[harryh]

Ya, babies/pregnancy are (in my mind) a subset of my point #2. For those (and a few other) reasons women tended to pay more for health insurance then men so some people are in favor of a social insurance system to even that out.