If you are expecting a refund you can check the IRS website Where's My Refund 4 weeks after mailing your return.
http://www.irs.gov/Refunds
If you are not expecting a refund tracking your return can be a little more complicated. You can use the IRS's new online transcript request option to tell when your return has been processed. Once the return shows up in the transcript request the IRS has received and processed your return. Before that time it will show that you have not filed for the year. You can also judge by when the IRS processes your payment (if a tax payment was sent/due)
http://www.irs.gov/Individuals/Get-Transcript
After 2-3 weeks have passed you may also call the IRS customer service line at 1 800 829 1040 to inquire regarding the status of your return.
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