Get your taxes done using TurboTax

When you enter your K-1 into TurboTax, on the screen with box 14 you enter your code I and code Z, but you don't need to enter any amounts on that screen.  Continue on through the interview, and after a couple of screens asking about your qualified business income, you'll come to the screens "We need some information about your 199A income or loss" and "Let's check for some uncommon adjustments" screens (see two screenshots later in this post).

Your Statement A amounts will go on the first screen, and your Statement C amounts will go on the second one (uncommon adjustments).  When you select the line with Schedule C on that "uncommon adjustments" line, boxes will "open up" to enter both your Schedule C amounts.

To get back to the K-1 summary screen and find the Schedule K-1 to edit, click the "magnifying glass Search" icon on the top row, enter "k-1" in the search window and press return or enter, and then click on the "Jump to k-1" link to find the K-1 you need to edit.

Here are screenshots for the "We need some information about your 199A income or loss" and "Let's check for some uncommon adjustments" screens where you enter the information from your K-1: