Yes, you will have to pay New Jersey taxes on the pension, but you will get a credit for the taxes paid to California. A word of caution, you probably will not get the full credit for the CA taxes since NJ has a lower tax rate.
For future tax planning, please see if you can get the payor of the pension to not withhold CA taxes since you are a resident of NJ.
Alternatively, you can try to file non-resident for CA and put in a claim for all of the CA taxes withheld, but CA is very aggressive and assertive on trying to tax money that they believe is "CA" income.
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