50万免税只对自住房有效，我孩子上学的地方离我十万八千里的，用他的名字买，他住那里是自住房，2年以上卖掉，所有不超过50万的增值都不用交税。

The IRS treats second homes differently when calculating capital gains tax. Second homes that are not used as primary residences, including vacation homes and investment properties, are considered to be capital assets under IRS rules.