So its a crap shoot - your small group is very likely to be cheaper, 99% of the time. The only important thing is, can your group actually support a real medical emergency at full cost? That's the only reason to join the group after all.

When participating in a larger insurance group, these same costs are born solely by insurance premiums. But the costs are not the same - big insurance companies have negotiated lower prices across the board. Your group cannot.

I see p2p insurance as a total loss, because in time of need they cannot possibly pay.

From what I'm reading, it sounds like the p2p insurance is intended to cover a portion of the deductible. This would allow the members of the pool to choose higher deductible plans than they would otherwise be comfortable with. If someone develops a chronic illness which is expected to always eat up the pool they would probably be booted after the first year.

Whoa - isn't that illegal now? Preexisting condition can't prevent an insurance group from admitting a new member? Or is that restricted somehow?

I have no idea what the legality of it would be, but it probably wouldn't make sense to accept or keep someone with an expensive-to-treat condition in small pool like that because there may not be enough other members to absorb the cost.

The whole point is that everybody has coverage under a high deductible standard insurance plan (which will be significantly cheaper than a low deductible plan), and then the group shares the risk of the deductibles.

Best case, everybody pays less for insurance (including what they pay into the p2p pool). Worst case, someone gets sick and busts the pool (and gets kicked out if it's chronic), but everybody still probably paid less overall. Not sure how well this works if the person who got booted can't get their deductible reduced.

I think health insurance is weird in a number of ways for this. It'd probably be great for e.g. homeowners insurance.

Wow, that's insane! I hope you guys (I'm assuming USA) fix this system soon. In countries with a developed health care system, this sort of thing does not happen.