TurboTax is showing that that 88% of my federally taxed pension is not taxable in Massachusetts. Is that correct?

It is possible.

• Is this from a traditional IRA?
• If so, you did not get a tax break in Massachusetts for the contribution.
• You would have to post it to the Massachusetts return, but that contribution will not be taxable when you withdraw it.
• This does not apply to 401Ks or other employer provided retirement accounts.