Show your card whenever you get medical care. This will assure that a claim for payment is sent to Medicare. Make sure to use your exact name and claim number. If you are married, your spouse will have his or her own card and claim number. Never let anyone else use your Medicare card, and keep the number as safe as you would a credit card number. Take your card with you when you travel, and have it handy when you call about a Medicare claim. Note: CMS began using cards displaying the 1-800-Medicare number. If you have a card that shows something different, it is still valid and can be used to get medical care.