I’m a PhD student in the CS program.
I’m a Master student in the CS program.
I study for a PhD degree in CS. 注意这里不用’s。
I study for a Master’s (degree) in CS. https://ell.stackexchange.com/a/267699/65098
I read for a Master’s degree in CS.
I read for a MSc degree in CS.
I study for a Bachelor’s degree in EE.