Where can I get Medicare Id to use on MA state healthcare requirements?

Medicare ID cards are issued by the Social Security Administration.

https://blog.ssa.gov/get-a-replacement-medicare-card-on-my-social-security/

You may call the MassHealth Customer Service Center if you don't have your MassHealth ID number, you will need to provide your social security number or your name and date of birth.

The phone number for the MassHealth Customer Service Center is 800-841-2900