Magento announced their support policies for Magento 1 installations today. From their blog:

We understand that many of our Magento 1 merchants need additional time to make the transition to newer versions of Magento. To that end, our software support policies ensure that those customers have the time and confidence to upgrade when it is right for their business. In particular:

For Magento Commerce 1 (formerly known as Enterprise Edition):
For Magento Commerce 1, we are providing software support through June 2020. Depending on your version, software support may include both quality fixes and security patches. Please review our Magento Software Lifecycle Policy to see how your version of Magento Commerce 1 is supported.

Magento 2 has been in stable release for about two years, and it’s time to find out what advantages your business can enjoy by moving on to the latest version! Contact us for help planning your transition to Magento 2.