Many customers prefer a predictable annual cost. When you purchase a perpetual license, you can purchase maintenance, which is renewable annually. Provided you keep your maintenance current, you will receive the next release of Stata automatically and without an additional charge.
Should you decide you no longer want to purchase maintenance, you may still continue to use your perpetual license. When there is a new release, you will be given the opportunity to upgrade to it by paying an upgrade price.
Maintenance may be purchased only when you buy a new licenses or upgrade an existing one.