Did you know Medicare only covers 80% of your medical costs? If you’re approaching your 65th birthday or planning your retirement, it’s important to understand what Medicare covers so you can protect yourself from unexpected medical costs. Supplemental health insurance plans help cover the 20% that original Medicare Parts A and B do not pay. Plan options have standardized letter identifiers to make it easy to compare price, deductibles, copayments, coinsurance and foreign travel.