http://www.irs.gov/taxtopics/tc156.html?portlet=1
US tax returns
Transcripts for federal returns can be obtained by calling (800)–829–1040 or by mailing form 4506-T (PDF), and should be received within approx two weeks . There is no charge.
But if you want a copy of the forms you sent to the IRS, then there is a fee of $39 per tax year requested.
You usually do not need a copy. A transcript is enough : it's a piece of paper that summarizes your return into a standard format so that's easy to read for an immigration officer.
Remember that the USCIS is not the IRS. Meaning that an immigration officer just wants to see if you filed ( complied with tax laws ) or not. A transcript is a true proof that you filed, as it comes from the IRS. If you bring a photocopy you made of your returns ( here, I mean a copy made by you, not a copy you would have paid for to obtain from the IRS ), it does not necessarily mean you filed a return.
Also, if you made a few mistakes ( wrong form, late filing ...), the immigration officer won't probably notice if the IRS hasn't.
Transcripts for state taxes also exist. See your State's Department of Revenue.
You may or may not be asked for them. I wasn't for CP in Paris, but maybe that's because my husband and I were students ( F1 ).
My opinion is still to be overprepared: if you do not have them, and are asked about them, what will you do ?!
Besides, there is no charge, so there is no reason not to request transcripts.
Quote From "CATSEYES":
http://www.immigrationportal.com/showthread.php?t=215048