Client is a cash-basis s-corp with one shareholder/employee. Filing of 2016 form 1120S has been extended. Business profits are $20,000 and the shareholder's W2 is $36,000 in box 1. Shareholder wants the s-corp to make a contribution to his SEP. It looks like the calculation is $9,000 ($36,000 x 25% max). Since the s-corp has a valid extension, would this $9,000 SEP contribution be deductible on Line 17 of the 2016 form 1120-S for this cash-basis taxpayer?