New to Medicare

What is my Medicare claim number?

Medicare claim number which is also known as Medicare Beneficiary Identifier (MBI) is the number that Medicare uses to file your claims. MBI are numbers and upper-case letters that you may find on  your Medicare card. If you enrolled in Medicare prior to 2018, you should have received a new Medicare card. The MBI used to be your social security number with a letter after it. Between April 2018 and April 2019 the CMS (Centers for Medicare & Medicare Services which is governmental agency that administers Medicare) mailed new Medicare cards which had a new MBI instead of your social security number to prevent identity theft and tax payer fraud.