It depends on the year of death, but for 2013, no return is required unless the gross estate (all assets, including life insurance proceeds) exceeds $5.25 million. The return and any tax are due nine months from the date of death, although one can apply for an automatic six month extension to file (not pay). North Carolina follows the same rules. Even if a return is not required, it might be advisable to file one to preserve the unused exemption of the first spouse to die.
Mr. Herman-Giddes is 100% correct. I would strongly suggest hiring an attorney to help you handle the estate matters, especially for an estate of this size.
This is not legal advice nor intended to create an attorney-client relationship. The information provided here is informational in nature only. This attorney may not be licensed in the jurisdiction which you have a question about so the answer could be only general in nature.
Visit Steve Zelinger's website: http://www.stevenzelinger.com/