“I moved back home, so I’m done with the U.S.” It is one of the costliest assumptions a green card holder can make. Leaving the country, letting the card expire, or shelving it in a drawer does not end your U.S. tax residency. Only a formal event does. Until then, the IRS still expects a return on your worldwide income, and sometimes years of back filings.

Congress has officially passed H.R. 1 – the “One Big Beautiful Bill”, and it’s now law. This sweeping tax legislation makes many of the...