Are y'all ready for another Medicare Mystery magically turning into a super simple "bear" necessity of Medicare. What in the world is co-insurance. I am constantly talking about how Medicare is unique from any other coverage we have ever been allowed to buy because it is completely transparent. All of your coverage is public information. Co-insurance is the amount that you pay of the medicare approved amount of a bill that is left after Medicare pays. This is usually a percentage, but you can estimate down to the dollar what each Medicare expense will mean for you. Not only are these expenses public information aka transparent... they are universal... as in everyone has the same exact coverage. Fun fact that you should know also is that Original Medicare operates with an administrative overhead of under 2%. That means that over 98% of every penny you or anyone else pays into original Medicare goes to the actual cost of care. This definition only applies to Original Medicare. If someone surrenders the right for Original Medicare to pay claims, the coverage is not at all public information or predictable and a whole other world to define on a whole other day. For now... co-insurance should be fairly simple oh and by the way, a medigap aka Medicare Supplement can usually pay the coinsurance for you. If you have more co-insurance questions, SCHEDULE A CALL with Mama Bear.