J.K. Lasser's Your Income Tax 2013: For Preparing Your 2012 Tax Return

1.15 Return for an Incompetent Person

A legal guardian of an incompetent person files Form 1040 for an incompetent whose gross income meets the filing tests on page 3. Where a spouse becomes incompetent, the IRS says the other spouse may file a return for the incompetent without a power of attorney, if no legal guardian has been appointed. For example, during the period an individual was in a mental hospital, and before he was adjudged legally incompetent, his wife continued to operate his business. She filed an income tax return for him and signed it for him although she had no power of attorney. The IRS accepted the return as properly filed. Until a legal guardian was appointed, she was charged with the care of her husband and his property.

The IRS has accepted a joint return filed by a wife in her capacity as legal guardian for her missing husband. However, the Tax Court has held that where one spouse is mentally incompetent, a joint return may not be filed because the incompetent spouse was unable to consent to a joint return; an appeals court agreed.