I moved to UT from CA last year and this year the company I used to work for got bought out and they are closing out a defined benefit program all of the employees were a part of. I will be receiving a lump sum cash out for my portion. Next year when I file my taxes, will I claim the lump sum as income on my Utah State Tax Return or will I need to file a CA Return and claim it there?

While the state, UT, where you bought your pension may not tax your retirement income, you may still have to pay taxes on the income in your state of residency of CA . For example, if you earn a pension in UT, then move to CA , the state of CA may require you to pay taxes on this income.

Well UT is my state of residency now. I didn't have access to the money until they closed the program when the company got sold. Since its a lump sum payout and I'm not rolling it over, I just want to see if I'll need to claim in in UT or file a CA return as well.

As you said WHEN you file your next year return I mean your 2018 return, you need to report the income on yur UT return since you as a full year resident of UT DO NOT need to file CA return any longer.