回复：父母绿卡

再次请教8老师，
 

I-864表，Part6, 14(optional), should I check?
-Up to you. If you provide the copy of your tax return of 2012 and 2011, then check it.

Where I can get the most recent tax years' federal tax return forms?
-Don't you keep the copies of tax return every year you filed to IRS? If no, you may get the tax transcripts from IRS.
See this website for tax transcript:
http://www.irs.gov/Individuals/Get-Transcript

My parents' I-94 due date is in the beginning of June. Is it OK I file all I-130,I-131, I-485, I -864 in May? 
-Yes. Anytime is OK.

 just before the expired date should be OK?