You may find this at http://uscis.gov
http://uscis.gov/graphics/howdoi/spouselive.htm
Information for Lawful Permanent Residents
If you are a lawful permanent resident and your petition for your spouse is approved, your spouse will be notified by the Department of State when a visa number becomes available. If your spouse is outside of the United States at the time of notification, he or she must then go to the local U.S. consulate to complete visa processing. If your spouse is inside the U.S. through a lawful admission or parole and is maintaining that status at the time of notification, he or she may file the Form I-485 when the visa number becomes available. If that is not the case but the petition was filed on or before 04/30/01, he or she may be eligible to benefit under section 245(i).
If you do not have the visa number issued by the Department of State, you must wait for a number to become current. Your spouse may need to depart the United States to avoid accruing unlawful presence. For more information, your spouse should refer to How Do I Become a Lawful Permanent Resident While In the United States?
If you were married to your spouse before you became a permanent resident, your spouse may be eligible to receive following-to-join benefits. This means that you would not have to submit a separate Form I-130, Petition for Alien Relative, for your spouse, and your spouse would not have to wait any extra time for an immigrant visa to become available. See Petitioning Procedures for more information on following-to-join benefits.
http://uscis.gov/graphics/howdoi/Appproc.htm#Following
Following-to-Join Benefits for Spouses
Please note: This section is only applicable to lawful permanent residents who did not gain their LPR status as an immediate relative (parent, spouse, or unmarried child under 21 years of age) of a U.S. citizen.
If you were married before you became a lawful permanent resident, and your spouse did not physically accompany you to the U.S., your spouse may be eligible for following-to-join benefits. This means that you do not have to submit a separate Form I-130, Petition for Alien Relative, for your spouse, and your spouse will not have to wait any extra time for a visa number to become available. In this case, you may simply notify a U.S. Consulate that you are a lawful permanent resident so that your spouse can apply for an immigrant visa. Your spouse may be eligible for following-to-join benefits if your relationship still exists and if one of the following is applicable:
You received a diversity immigrant visa
You received an employment-based immigrant visa
You received an immigrant visa based on your relationship to your U.S. citizen sibling
You received an immigrant visa based on your relationship to your U.S. citizen parent when you were already married
(For information on following-to-join benefits for children of lawful permanent residents, please see Petitioning Procedures: Bringing a Child to Live in the United States.)
If you fall into one of these categories, please submit the following information to the U. S. Citizenship and Immigration Services:
Form I-824, Application for Action on an Approved Application or Petition
A copy of the original application or petition that was used to apply for your immigrant status
A copy of the I-797, Notice of Action, for your original application or petition
A copy of your alien registration receipt card or I-551
If the I-824 is approved, the USCIS will notify a U.S. consulate that you are a lawful permanent resident so that your spouse can apply for a following-to-join immigrant visa. Your spouse must then contact the local U.S. consulate to complete the processing.
You should file the I-824 at the USCIS office that took the most recent action on your case.
