As stated in the Adobe Support Lifecycle Policy, Adobe provides five years of product support, starting from the general availability date of Adobe Reader and Adobe Acrobat. In line with this policy, support for Adobe Acrobat 11.x and Adobe Reader 11.x ends on October 15, 2017.
End of support means that Adobe no longer provides technical support, including product and/or security updates, for all derivatives of a product or product version (localized versions, minor upgrades, operating systems, dot and double-dot releases, and connector products).
Subscription plans are the best way to take advantage of everything Acrobat has to offer. New annual and month-to-month subscription plans make Acrobat more affordable than ever, while also giving you access to premium Adobe Document Cloud services. If you own Acrobat Pro XI – or Acrobat Standard XI – you also qualify for a reduced price when purchasing a perpetual (one-time) license. A one-time purchase includes desktop software and lets you work with free Adobe Document Cloud services only.