Peter. I didn't know the tax rule only until I started researching it. So do not buy a home in the US before you sell you home in Canada, otherwise your home in Canada will not be your primary home anymore after you bought your US home. Also you must indicate your move to the US was for employment, it is true for most of us anyway. Also I read the US-Canada tax treaty, IRS should only consider capital gain at the FMV (Fair Market Value) when you left Canada (same for CRA). This is not said clearly in IRS rules, but it's in the US-Canada tax treaty.