I am in almost the exact same situation as patelshyam2002. I was a resident of Pennsylvania from January 2021 through September 2021. I then physically relocated to California for a job in October 2021 and was a resident there through the end of the year. When I was in PA I received the COBRA premium assistance subsidy for 4 months. All of the COBRA subsidies I received were received while I was a PA resident.
Please note that I am not a tax professional and am new to CA as well, but looked into this a bit and the solution appears to be the following. As part-year residents, we are required to fill out the "California Adjustments - Nonresidents and Part-Year Residents" part of California Schedule CA (540NR), which has separate columns (columns A-E) corresponding to "Federal Amounts", "Subtractions", "Additions", "Total Amounts Using CA Law As If You Were a CA Resident", and "CA Amounts". Based on information I found on the CA Dept. of Revenue website, it looks like we need to put the dollar amount we received for the COBRA subsidy on line Z (other income) for item 8 in section B of part II. Be sure to put it only in column C and put "COBRA subsidy" in the blank space immediately to the left of column A. Then, put $0 in column E (amount received as a CA resident). From what I can tell, this is done because CA requires us to calculate all of our worldwide income for 2021 whether it was subject to CA taxation or not in order to calculate our effective tax rate. They appear to only use the amount for that purpose and do not actually tax the COBRA subsidy if you put $0 in column E.
One caveat is, as many people have noted, it is not easy to determine the dollar amount of your COBRA subsidy if you never were on COBRA before the subsidy or after the subsidy because the COBRA administrator was not required to send us anything showing amounts paid on our behalf (e.g. no monthly COBRA premium statements with dollar amounts were ever sent to us as recipients since no amount was due: it was fully paid for us by our former employer). If this is the case for you, you may need to contact your COBRA administrator to get a dollar amount that you can then use on your CA state income tax return.
If you ever find out that the method I indicate above is correct, please let me know.
