Turbo Tax told me to mail forms 8453 and 8949 to the IRS. Do I need to include the documentation behind form 8949 as well? Thanks.

Yes, you will need to include documentation for the asset sales you reported along with your Forms 8453 and 8949.  

If you report your investment sales using the summary total method, then you need to send the supporting documents showing the details of each sale. Usually, your Form 1099-B will have the needed information including: 

• Description
• Date Acquired
• Date Sold
• Sales Price
• Cost Basis
• Gain or loss for each sale
• A sale category based on how the sale was reported to you and the IRS

The information should be mailed to:

 Internal Revenue Service
 Attn: Shipping and Receiving, 0254
 Receipt and Control Branch
 Austin, TX 73344-0254