A list of model programs can be found here***: https://www.seas.harvard.edu/academics/graduate/phd-model-programs
Do I have to follow the model program?No***. Model programs are there as a guideline. For some, this may match perfectly to your research needs. Others will need to take alternative classes to help with research. If you follow the model program your program is guaranteed to be approved by the Committee on Higher Degrees (CHD). If you deviate, your course of study may not be approved by the CHD depending on how large your deviation is. If classes are 200 level and taken within SEAS it it is more likely to be approved. Students often take classes at MIT, but be sure a similar course isn’t offered at Harvard first. Ultimately you should take classes that are going to improve your research and not strictly adhere to model programs out of convenience.
***: Note that CS has Program Guidelines rather than Model Programs, which are more prescriptive. Please visit: https://www.seas.harvard.edu/academics/graduate/phd-model-programs/phd-program-guidelines-computer-science
