I recently upgraded from 12.1 to 12.6 (I know--shouldn't have waited so long) and didn't have any issues. From what I know, you don't need to install upgrades between your current and target version.
I used the above link when I upgraded--I know it references upgrading to 12.5 but it worked well.
Best of luck!
Thanks for the info! I will check out the link. Thanks again.