I had the same question....client lived in NY and worked in NY part year, lived in NY and worked in NJ part year and then moved to NJ and worked in NJ rest of year. Need to file Part Year Resident NYS return, Part Year Resident NJ return and Part Year NJ Nonresident return. Can not see how to generate both NJ returns.
The original post only mentioned part year resident, not part year non resident PLUS part year resident.
TU added more info that wasn't in the original post.
You will need to file both, but you will probably need two tax files.
That's not true. Per the State of NJ, if a taxpayer earned income from NJ while both a resident/nonresident they are required to file both NJ-1040 and NJ-1040NR with the State of NJ. I don't think ProConnect has the ability to process.
"If you received income from New Jersey sources during both your residency and nonresidency periods, you must file both a NJ-1040 and a NJ-1040NR. You must report the income you received during the time you were a resident on your resident return. Report the income received while you were a nonresident on your nonresident return."