Finally Turbotax employee Linda zeroed in on the solution to the problem. So Patricia V's answer was correct but incomplete--you enter Z but disregard Turbotax's instruction to also enter the amount of income on that same line. On another page you check the box about Statement A and then receive the proper box to enter the 199A income. Obscure, but as a scientist, I find a lot of tax accounting instructions to be obscure.
