No, don’t file for the both of you.
You’ll actually have to make a calculation to come up with your figure.
According to Change in filing or marital status in the 2021 Oregon Income Tax - Form OR-40 Instructions, [s]ome taxpayers who filed a joint return for 2020 must prorate their kicker based on their share of 2020 federal AGI.
Table 8 in the instructions indicates that you would need to complete Parts A and B of the Kicker worksheet, since your filing status changed from “Joint” to “Non-joint.”
In Part A of the Kicker worksheet (see the link above), Line 1 is Tax before credits, which you take from Line 22 of your 2022 Form OR-40. Line 3 of the worksheet is your total personal income tax liability for 2020.
