Trust tax return required?

Mom passed away-left all assets in inter vivos revocable trust, including some money market funds and a condo. Sibling and I are beneficiaries. We sold condo for $xxx,xxx and got a 1099 from closing attorney. Sale was just months after her passing, so cost basis is equal to sales price. Is the gross income of the trust the amount of the sale reported on 1099? Or, do we net out basis and have $0 capital gain, and therefore are below $600 in gross income? Other income in trust was negligible. The return will show $0 tax liability, but should we file anyway since the 1099 will be reported? Thanks.
Date: Sat-Jan-7-2017-
Filing requirement based on gross not net. You should file a tax return. 
[d] By: interpreter
Date: Sat-Jan-7-2017
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