Correct. Wait for 2013 SP5.0 for interoperability between 2014 and 2013.
Read the help file for the limitations of this functionality: http://help.solidworks.com/2014/English/solidworks/sldworks/c_previous_release_interoperability.htm
Make sure you read and thoroughly understand the help file link Alin posted.
The interoperability between SW13-SP5 & SW14 files is VERY limited.
Alin- Thanks for the help.
Kelvin- Agreed. I will be waiting until all of my department upgrades to avoid headaches.