Most Nissan Altima vehicles sold in North America for the 2013-2015 model years have push-button start and use a factory keyless entry “Smart Key” remote transmitter with FCC ID KR5S180144014. Some Altimas during this period have remote start and some do not. See 2013-2015 Altima proximity remote keyfobs at this link: http://www.remotesunlimited.com/specify.php?search=1&type=fcc&search_fcc=KR5S180144014.
Nissan Altima systems using this remote require programming with a scan tool, so you will need to take your vehicle and all remotes used with it to a dealership or locksmith to have this done.
Note that parts with the same FCC ID were used on Infiniti vehicles.