I received my Green Card about 2 years ago, with the help of your excellent of Complete Do-It-Yourself Package of EB1-Extraordinary Ability. Now, my company needs to send me to work in my home country for about 3 years. My question for you is: how to keep my Green Card status while working in my home country? Thank you very much. 

As a US permanent residents who are abroad for a year or more, USCIS requires the Green Card holders to apply for a Reentry Permit in order to return to the United States. Additionally, such permanent residents must establish that they, in fact, do reside permanently in the U.S. Since the Reentry Permits must be requested from within the U.S., permanent residents who plan to travel for extended periods should request their Reentry Permits prior to departure. 

There might occasionally arise a situation in which a permanent resident intends to return to the U.S. in less than a year, but is unable to do so. In such a situation, the Returning Resident Visa (SB1) may provide an option. The requirements for the Returning Resident Visa are very strict. Eligible individuals are those permanent residents who have remained outside of the United States beyond a one-year period for reasons beyond their control.