I have the same question, and was told by TurboTax phone help today that I could take the SEP deduction based on the K-1 (1065) box 14 A Self Employment Income. There is no box 13 amount for a retirement plan established by the Partnership. I am a limited partner with material participation if that matters.
TurboTax is allowing the deduction based on that income flowing to the sched SE Self Employment Tax computations. It’s even calculating a max SEP contribution based on this box 14 A income. I have a small amount of Schedule C income but the magnitude of the maximum deduction suggests it can only be coming from the K-1 box 14 A self employment income.
I would say there is an error in the program if this deduction is actually not allowed.
