Traditional IRA Basis if rolled over 401K and employer pension benefit?

Hello,

 

I did my first Roth conversion this year and while reviewing my most recent traditional IRA basis on form 8606, I realized I never factored in two types of rollovers I have done in the past from employers: a 401K including both employee and employer contributions, and an employer pension plan vested benefit which was from employer only contributions.

 

Do either of these two types of rollovers into a traditional IRA affect the basis of the IRA? I know the basis affects the taxable portion of the Roth rollover I did.

 

Thank you for your help.

 

(I reviewed previous questions but none seemed to be just like my situation.)