Regarding this, how long can you stay out of the US with a green card?
6 months
Likewise, is a green card holder a US national? A Green Card holder is an individual who is not a US citizen or US national, but who is residing in the United States under legally recognized and lawfully recorded permanent residence as an immigrant.
Similarly, you may ask, can you lose permanent resident status us?
Lawful permanent residents can lose their status if they commit a crime or immigration fraud, or even fail to advise USCIS of their changes of address. The short answer to your question is yes, you can lose your green card.
What is permanent resident status in USA?
A Green Card holder (permanent resident) is someone who has been granted authorization to live and work in the United States on a permanent basis. As proof of that status, U.S. Citizenship and Immigration Services (USCIS) grants a person a permanent resident card, commonly called a "Green Card."