If you have taken any trips outside the United States that lasted six months or more since becoming a Permanent Resident, send evidence that you (and your family) continued to live, work and/or keep ties to the United States, such as:
• An IRS tax return "transcript" or an IRS-certified tax return listing tax information for the last five years (or for the last three years if you are applying on the basis of marriage to a U.S. citizen).
• Rent or mortgage payments and pay stubs.

International Travel
A Permanent Resident of the United States can travel freely outside of the US. A passport from the country of citizenship is normally all that is needed. To reenter the US a Permanent Resident normally needs to present the green card (Permanent Resident Card, Form I-551) for readmission. A reentry permit is needed for reentry for trips greater than one year but less than two years in duration.

Maintaining Permanent Residence
Maintaining Permanent Residence You may lose your permanent residence status if you commit an act that makes you removable from the United States under the law in section 237 of the Immigration and Nationality Act. If you commit such an act, you may be brought before the immigration courts to determine your right to remain a Permanent Resident.

You may be found to have abandoned your permanent resident status if you:

* Move to another country intending to live there permanently.
* Remain outside of the US for more than one year without obtaining a reentry permit or returning resident visa. However in determining whether your status has been abandoned any length of absence from the US may be considered, even if it is less than one year.
* Remain outside of the US for more than two years after issuance of a reentry permit without obtaining a returning resident visa. However in determining whether your status has been abandoned any length of absence from the US may be considered, even if it is less than one year.
* Fail to file income tax returns while living outside of the US for any period.
* Declare yourself a “nonimmigrant” on your tax returns.

SInce nobody replied, ii will just post what i found related to topic

http://www.uscis.gov/portal/site/uscis/men...00045f3d6a1RCRD


I guess main proof would be taxes for the years of absence?

You had no residence in the US while you were abroad.... showing that you stored your things at a relitives house just confirms that you did not maintain a residence in the US... it could be deemed that you abandoned your Greencard status... I do not know if they will accept the fact that you were at school abraod... did you do any work while abroad?

Kez

Anything over 6 months is very tricky. Some people have done it and others have failed. It's all on what you can do to prove it (and I don't think the letter from the grandmother will mean anything to them)...

There are many sites out there if you google "Continuous residency requirements" or similar. One is the INS page http://tinyurl.com/y69toj another is at http://tinyurl.com/y69toj where many people talk about breaking the continuous residency.

There is a good site (you'll have to google it) that talks in depth about this. Basically comming down what so many others have talked about as well where 0-6 months gone the INS has to prove that you didn't break your residency. 6-12 months gone, you have to prove to the INS you didn't break continous residency and over 12 months it's almost guarenteed it will be denied.

Also remember you are jeopardizing your Green Card as well by being out, but if you had gotten the Re-entry permit (not sure if you did) that can at least preserve your Green Card. So those are a few places to look, but many people have been getting denied now based on being out of the country too long and loosing all that money. Basic rule is never leave more then 6 months unless it's a dire emergency or if you do, wait a few more years to apply...