A statement from the project said there would be no further security updates for Jessie, though a small set of packages would be supported by external parties.
Debian releases are named after characters from the film Toy Story. The current stable release is known as Buster or version 10.
Debian spokeswoman Laura Arjona Reina said the LTS team would prepare the transition to Stretch or version 9 which is the old stable release.
"Debian 9 will also receive long-term support for five years after its initial release with support ending on 30 June 2022," Arjona Reina said.
"The supported architectures remain amd64, i386, armel and armhf. In addition we are pleased to announce, for the first time support will be extended to include the arm64 architecture."
Debian was founded in 1993 by the late Ian Murdock as a community Linux distribution. It now has thousands of volunteers, is available in 70 languages and supports a multitude of architectures.