So, in your 30s? My parents both had cancer in their late 50s/early 60s (including surgery / chemo) - and paid like $15 for some pain meds in Canada.

Even on a pretty good Kaiser plan, we're paying $200+ per day in the hospital, etc. On a high-deductible, more. They say they have a $1M annual limit, but that they've never enforced it. I hope we never have to find out.

Yes, I would get insurance once I have kids and that would cover the 50s+ when people usually start needing it.

But do you want to take the chance that you will never have major medical expenses between the time you retire early and you are 65 and eligible for Medicare? How many of your friends are over 50?

Very few, I am just saying that you can sign up when you think the risk hits your threshold. I'm mid 30s and wish I hadn't had to pay the last 10yrs. Honestly, until you have ids it's unlikely you'll use it and even less likely that you can't sign up for it before a major operation.

Yes you should try to time a major medical issue or accident during the open enrollment window. You should also not have car insurance until you think you might have an accident