Some MicroMasters® programs have suggested prerequisites. To find out about prerequisites for a specific MicroMasters® program, please review the program's introduction page.
Regarding prerequisites for a single course, you can read more here.
For most programs, the prerequisites are suggested and not checked or required. If you do not meet the prerequisites you are welcome to join the courses and try your best.
For more information, see the edX MicroMasters® page.