Starting today, AWS CloudFormation StackSets enables you to import existing CloudFormation stacks into a stack set. StackSets extend the functionality of stacks letting you create, update, or delete stacks across multiple AWS accounts and regions with a single operation. You can now bring your existing CloudFormation stacks into the management purview of a new or an existing stack set to easily create resources, applications or environments in other AWS accounts and AWS Regions. That way you can avoid the process of manually replicating and managing the infrastructure in each account and region individually. For example, you can import security resources such as AWS IAM roles described in CloudFormation into a stack set and then centrally manage and deploy those IAM roles across multiple accounts to achieve a consistent organization-wide security compliance in a scalable manner.
Source:: Amazon AWS