the treaty in no way affects the taxes you pay in the US on the gain. under the treaty, I believe if you are a resident of Germany (under their tax laws) and sold real estate (like your home) in the US then Germany grants a foreign tax credit under the treaty. under the treaty and German tax laws, there may be a limit to the credit granted. if you want more info you need to seek advice from someone who knows the treaty and German tax laws. I would also say DIY software is probably not appropriate for ex-pats. they don't ask the right questions. for example if you were to receive retirement benefits from Germany, they are also affected by the treaty as to where taxable and I'll bet TT nor any other DIY app will ask questions to determine where it's taxable. as a matter of fact, even pro software doesn't ask questions but is dependent on the preparer's knowledge of the tax laws and treaties.
