We filed as single in both 2010 and 2011. Shouldn't his accountant have the answer to the questions I'm posting. He is a CPA and did my spouse's taxes for years. Would an estate attorney have the answer?

His CPA will not necessarily provide you with information. However, you can ask him. An estate attorney probably would know this. A tax attorney certainly would know this. So would a family law attorney.

Thank you!