"• Adjustment based on being the derivative spouse or child of a principal applicant:
If you are currently in the U.S. you may file your Form I-485 simultaneously with the principal applicant or you may file at any time after the principal applicant has been approved, if a visa number is available."
The only part I don't understand is "if a visa number is available". Can someone clarify what that means?
Only a limited number of visas are available in each "preference category" each year. Unless, you are the "immediate relative" of a qualifying USC for whom visas are unlimited, your wait will depend on how many visas are available. It varies by country. Do consult an experienced immigration lawyer for a consultation,
It means that the priority date must be current.
For the latest visa bulletin see http://www.engnishimura.com/priority-dates/current
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.