You can buy it here. Be sure to pick Mac.https://turbotax.intuit.com/personal-taxes/past-years-products/
Or do you mean the Mac amend program? There is a link in this FAQ to fill out the Mac request form<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/2693844">https://ttlc.intuit.com/questions/2693844</a>