From what I understand, starting with V13 personal licenses will include 1 year free upgrades. I thought V12 licenses younger than 1 year will work with V13, but that's not the case. I like the IDE, but I will stick with v12 for now.
In the article linked it says "Both personal and commercial licenses now include 1-year upgrade subscription. For more information on the new pricing and licensing options for IntelliJ IDEA, please visit ..."