Do NOT try using the login found at the top of the page. Instead, simply scroll down to the Cannabis Control Card section and click "Apply for or Manage a New Medical Marijuana Card."
In the Medical Marijuana Registry section, click "Renew an Existing Card"
Note: you can request a replacement if your card is lost or damaged here too
Select either Adult Application or Minor Application
Complete the application
Pay the state fee of $20
You can do this via credit, debit or ACH
Once submitted, you will gain access to a temporary card which can be printed out - it is not valid in digital form
Once your application is approved, you will receive your new medical cannabis card from the Montana state in the mail