Co-Insurance: Shared expenses with the insurance company

Think of it like splitting the tab at a restaurant. You go out with a friend, eat and drink like a Viking, but you only pay for a side salad. You pay a small percentage of the bill; your friend pays the rest. That's how co-insurance works. If you have 80% co-insurance, you will pay 20% of the bill. Usually co-insurance doesn't kick in until you have paid a deductible amount. It's like having to pay the cover change to get into the all-you-can-eat buffet. Once you are in, you split the expenses with your friends.