What problems should I pay attention to when entering the United States with a US green card?

If you stay abroad for a long time, you must apply for a re-entry permit. If you stay abroad for more than one year, the green card can no longer be used as a valid entry document, and you have to pay a fine of $585.

You can sign this I-407 renunciation form. If you sign the form, it means that you formally give up your American resident status. You need to apply for a B 1/B2 tourist visa to enter the United States in the future, or apply for a green card again. If you don't sign the I-407 form, you need to submit the case to the immigration court, and the judge will decide whether you can keep your green card or be repatriated.