You can make TurboTax accept a standardized Swiss address; but you are also correct in that the program is really designed around the typical United States address format. That said, while you should be able to enter your Swiss postal / mailing address in full, you will not be able to enter your local telephone number, because TurboTax will not allow any number that is not in the US-style 3-digit area code + 7 numbers (e.g., 212-555-5555). Still, because a telephone number is not absolutely required by the IRS, even for US taxpayers living domestically, you can continue to file your tax return normally. Simply enter a "made up" number here if you wish, like they do in Hollywood films (with a string of 5's). That process will work.
Below you can find links to two of our TurboTax pages that discuss overseas tax returns for US citizens, as that information applies directly to you.
https://ttlc.intuit.com/questions/2579809-how-do-i-enter-a-foreign-address-in-turbotax
https://ttlc.intuit.com/questions/1900705-can-i-e-file-with-a-foreign-address
That said, also attached to this answer are two screen-capture images illustrating how I entered the mailing address for the Swiss National Bank into TurboTax, just by way of example. You should be able to extrapolate from that generalization to your own, unique address. Please keep in mind that certain characters used in the German, French, and Italian languages do not exist in the English character set. Thus, you may need to substitute a plain English "u" for a German glyph, U with an umlaut, for instance. You can use a colon, a semi-colon, or just a blank space or two in the main address line if you need to (see the screen-capture examples).
While you may need to be a little creative with foreign addresses in TurboTax, you can still create an acceptable tax return for filing and meeting IRS compliance in the United States.
Thank you for asking this interesting question.
