Well, yes, it's possible, but it seems like there are other questions you're intimating, but not explicitly asking.
Depending on the program, they might accept some of your master's program coursework in lieu of attending those courses in their program, e.g., exempting you from a stats course if you have already completed a comparable stats course. This often just involves the instructor in PhD class looking at your grad program syllabus.
They might also accept your I/O grad thesis, if you completed one, and not require you to complete another one during their PhD program, but again, it depends on the program.