I am performing my final review. I have two K-1 1065 forms which have Z *STMT in Box 20. There is no dollar amount listed so I put in 0. This is flagged?

No, this is not flagged, if what you mean by flagged is an item that draws IRS attention.

The notation *STMT in Box 20 is to make you aware there should be a Box 20 statement attached to your Schedule K-1. Code Z is for Section 199A information.

Generally, you may be allowed a deduction of up to 20% of your net qualified business income (QBI) plus 20% of your  section 199A dividends, and qualified PTP income from your partnership.

This can be a significant deduction, so you should check your Schedule K-1 carefully to see if you have a statement with the figures that you need to claim this deduction. 

look on the back of the k-1 for that statement.  some put it there and others put it on a separate page.