It all depends on how the income was reported. If the 1099s and SSA-1099s are in the decedents name and social security number and there is no filing requirement, then you are good to go. Theoretically, any income received after date of death should be reported on the estate's tax filing, form 1041. In a perfect world, at death, the decedent's assets should be re-registered into the name of the estate with a separate EIN so all income after that date would be reported to the estate through the 1099s. The estate would then report the income on the estate's tax return.
If you closed the estate and distributed the assets within 1 year, then you shouldn't have any problems not filing a return. Assuming all the income was reported to the decedent's social security number.
