From long experience....
When you license the software initially, you're offered the option of purchasing support (something like $60/year, I believe). The support gets you upgrades annually and the right to contact support for after the initial period is up. If you do not buy support, the software will NOT stop working. You simply won't get the upgrades without buying a license. Your version (14 right now, 15 in the first quarter) will not stop working. (But good luck finding help for something 5 versions behind. It's out there, but harder to find as most folks in the forum tend to be on maintenance and tend to upgrade.)
In either event, when they release a hotfix for your version, you'll get the hotfixes for free - they're generally just updated macro files.
I would strongly recommend the maintenance - it's a lot cheaper than the "new" fee, and there is generally not an upgrade option. There are enough new features every year to make it worth the $60 (or $5/month - how I justify it). Disclosure: I am nothing more than a customer who wishes he had bought the maintenance the first time, and most assuredly did the second time - I need those features.
Jim