An EIN was assigned to settle part of the estate of my husband who died in 2017. How will that EIN impact the tax return for married filing jointly in 2017?

The EIN will not be entered on your personal income tax return that you file with your deceased spouse on a married filing jointly (MFJ) return.  The estate return (Form 1041) is completely separate from your individual return for you and your deceased spouse. The estate return will use the EIN that was assigned to the estate. 

The income earned by your deceased spouse until the date of death is reported on your personal individual return.

From the date of death forward any income that he did not receive before death, but earned after death and before the estate is settled and distributed will be entered on the estate return under the EIN established for that return.  This does not include income that was jointly owned that immediately transfers to you upon death.