First of all, parents can only apply 4 years and 9 months after Oct 20, 2009.
Also, it seems that that their residency for naturalization purposes was in effect interrupted, more than once, by them having remained abroad for one year at a time. Thus, the law is that they must wait for 4 years and one day since their last entry before being eligible to apply.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
Eligibility for naturalization is generally 5 years after LPR status. The 3 year requirement applies if: 1) a permanent resident marries a US citizen who has been a citizen for 3 years, and 2) the couple has been "living in marital union."
Physical presence in the US is required for at least half of the 3-yr or 5-yr period. You should consult with an immigration attorney to discuss your case as not all facts are known in your case.
The above information does not constitute legal advice, and is intended only as general information. You should speak with an attorney to discuss your individual case, as not all facts are known at this time.
If your parents stayed in the U.S. a couple of months and left for over 6 months, they may not meet the physical presence and continuous stay requirements for seeking naturalization. More so, they may also be endangering their permanent residency. Consult with an experienced immigration attorney before they take the next trip abroad.
This response is general in nature and cannot be construed as legal advice, given that not enough facts are known. Any comments offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship. If you would like additional information based on this response, please contact my office at 510 657 7665 or 415 902 0832 to schedule a consultation.