This is a loaded question as it depends on your definition of "end of service". If you have current valid support you will be able to enjoy updated versions and Premier Support, as long as your support is active. If you don't renew your support you will be able to download versions that were released before your support expiration. So this is one aspect of "service".
Another aspect of "service" is bug fixes. We typically fix bugs in 3 versions, which means right now, in the 2017, 2016 and 2018. Sometimes we may fix bugs in earlier versions if we have critical customers who are using them.
Moving forward our intention, starting in 2018, is to support 3 legacy versions.
Please see: https://software.intel.com/en-us/articles/unsupported-product-compiler-and-library-versions and let me know if this answers your question.
Regards,
Noga - Intel Developer Support
