Copies of tax returns should be kept for at least 3 years.  The IRS can provide copies of prior year tax returns for a fee.

IRS Tax Transcripts are often necessary for applying for a mortgage or college financial aid.  If you need a tax transcript, the IRS will provide one for free.  Transcripts provide a summary of your tax return information and they are available for the most current year and the past 3 years.

Tax Transcripts can be ordered on-line, by phone, or by mail.  More information can be found here.