If you purchased an SDS MicroMasters Program Track Bundle, then you received a Paid Course Entitlement for the SDS Capstone Exam with which to upgrade your enrollment in the course. As long as you have not attempted the Capstone Exam course yet, and your Entitlement for the Capstone Exam course has not expired, then you do not need to pay for the course again.
Please note that, unlike the other courses in the SDS MicroMasters Program, enrollment for the Capstone Exam course is managed by the SDS Team directly—you cannot enroll yourself in the Capstone Exam course. The SDS Team will enroll you automatically into each upcoming session of the Capstone Exam course, for as long as you are eligible to take it.
If you already used your bundle's entitlement or it expired
If you did purchase the SDS MicroMasters courses as part of a Program Track Bundle, but you've already attempted the SDS Capstone Exam course, then your Paid Course Entitlement has already been expended in that attempt. The Program Bundle awards only one Entitlement—one attempt—for each included course. To attempt the SDS Capstone Exam course again, you must submit payment for the course again to upgrade your enrollment.
If you purchased the SDS Program Bundle more than 24 months ago, then your Paid Course Entitlement for the Capstone Exam course has likely expired. Entitlements issued as part of Program Bundle purchases on the MIT Learn platform expire after 24 months, but the SDS MicroMasters Program can usually work with reissue these expired Entitlements under certain circumstances.