I was married as of DEC 30, 2016. Would filing SINGLE be an issue for the year?

Someone who was legally married as of 12/31/2016 could file as married jointly, married separately, or head of household (again, if he or she meets the qualifications). But they couldn't file as single or qualifying widow(er). Please see the following TurboTax FAQ for more information:

https://ttlc.intuit.com/replies/3302320

Thank you for the answer, it helped a lot.

You are welcome.

Your marital status on the last day of 2016 determines your filing status for the entire tax year. Since you were married you can not file single. You must file married either jointly with your spouse or separately. Joint is almost always the most beneficial way for couples to file.