To amend a 2013 tax return, you will need to purchase one of our Desktop products located on this page:https://turbotax.intuit.com/personal-taxes/past-years-products/2013/
Prior year tax returns cannot be filed online.
You will need to enter the information from your 2013 return into the Turbotax program and then amend the return so Form 1040X will populate (these instructions are assuming you did not use TurboTax to file In 2013). To do this, select "Need to Amend a filed return" and on the next screen select "Start a new return to amend". You will start and complete a new return, then you will amend to add your dependent.
You will then mail Form 1040X along with supporting documentation to the IRS address listed on Page 14 of this link (mailing address depends on filing situation, please read through the chart to determine where to mail): https://www.irs.gov/pub/irs-pdf/i1040x.pdf
