State Residency Status for Graduate Student: OH, IL, or CA
We live in Ohio. My son graduated college in May 2018. He took a year off between undergrad and graduate school, taking a part time job as a pitching coach at a Junior College in IL that started in Aug 2018. In May 2019, he left his part time job in IL and moved back home to live with us in OH. Thus, he lived for 5 months (Jan-May) in IL. His part time IL job sent him a W-2 for $3.3k. We were supporting him while he was working part time in IL.
He was then accepted into a graduate school program in California (Cal State University Long Beach - CSULB). He started graduate school full time in Aug 2019. The graduate program is not on-line, i.e. it requires him to be physically present at the university to attend classes. He rents a bedroom in a condo in Long Beach, CA (we are not the condo owners). While in graduate school, he worked for the University for 4 months (Sept - Dec). They sent him a W-2 for $2.6k to the CA address where he rents. We continue to provide his support as well as pay for his schooling from remaining 529 funds. He was 23 yrs old during 2019. He still has his OH driver's license.
The CSULB sent a 1098-T with graduate student box checked and at least 1/2 time student checked.
So, couple questions:
1.) What State does he declare as his residency for the 2019 tax returns?
2.) How may State returns does he have to submit for 2019?