Microsoft provides a minimum of five years of Mainstream Support and five years of Extended Support for business and developer products.
During the Mainstream Support phase, all support options are available, including all paid and complimentary support options. Security updates and non-security hotfixes are provided at no additional charge.
During the Extended Support phase, paid support options continue to be available and security updates continue to be provided at no additional charge. However, customers who want new, non-security hotfix support during the Extended Support phase must sign up for Extended Hotfix Support.
The Extended Hotfix Support benefit for Software Assurance customers includes the annual fee for Extended Hotfix Support on specific products covered by Software Assurance.
Customers are not required to sign an Extended Hotfix Support agreement within 90 days of a product's transition from Mainstream to Extended Support. Instead, they can enroll at any time during the Extended Support phase for selected products for which they have Software Assurance coverage.
Learn more about the Microsoft Support Lifecycle