I'm assuming that the system we have here in godzone is similar, so think about this; When you reach retirement age, the payment required will start to increase, virtually annually, because they DON'T want your business. You will be on a pension and may be unable to sustain the increases, and you are much more likely to NEED medical treatment. Now the tricky bit.
They will NOT at this point change your policy to a hospital-only policy. Thay will only close that policy and begin a new one, Which will NOT cover existing medical conditions, even though the conditions developed whilst you were insured by them! Sneaky.

This has happened to me, and I now wish that I had realised it was going to, as I would have opted for the mimimum, hospital-only policy all the time. I would have been able to keep up the payments longer, and it was cheaper all the way through, anyway. My company made a virtually 90% profit out of me.

Do check the system your insurer operates.