I got K1 from 1120S that is showing loss of ($43,000), Can i claim that loss in my personal tax return?

You can claim a loss only up to your basis--$15,000.  The rest of the loss can be carried over until you have sufficient basis to take the rest of the loss.

Once you have utilized all stock and loan basis to deduct losses, you need to complete Form 6198 in TurboTax.  This will allow the program to compute the amount at-risk and track suspended losses for future years.

Form 6198 is for "At Risk" losses, not losses due to insufficient Basis.

The Moderators have told me that PQ has stated that TurboTax does not support losses in excess of Basis (and has no way to properly enter it in future years)

Thank you

Related question: TT Online instructs you to only enter the allowed loss in Box 1 of the K1.   I also need to enter information for 199A form (Box 17 Z)  Do I also adjust the loss amount to allowed (instead of actual)  in this form as well?