My husband passed away in January 2019. I never got his 1099 from Social Security. It was his only income.Can I file married filing separately or as single?

[VolvoGirl]

For 2018 you can still file as Married Joint.  Yes you need his SSA-1099.  Ask ss for it.

[Leonard]

You can file married filing jointly for tax year 2018.  You should get a copy of his SSA from the Social Security Administration and also if you have not done so notify them of your husband's death.