# Import stacks into CloudFormation StackSets
<a name="stacksets-import"></a>

A stack import operation can import existing stacks into new or existing StackSets, so that you can migrate existing stacks to a StackSet in one operation.

For *self-managed* StackSets, the import operation can import stacks in the administrator account or in different target accounts and AWS Regions. For *service-managed* StackSets, the import operation can import any stack in the same AWS Organizations as the management account. 

The following are considerations and limitations when importing stacks into StackSets:
+ The import operation can import up to 10 stacks using inline stack IDs or up to 200 stacks using an Amazon S3 object.
+  The `NoEcho` property is not supported. Stacks that contain `NoEcho` won't be imported into new StackSets through StackSet import.
+ Stacks can only belong to one StackSet.
+ You can implement stack tags to the StackSet by specifying tags explicitly as parameters in the stack import operation.
+ A stack's custom parameter overrides aren't affected during the import operation.
+ Parameters of imported stack instances can't be updated using the **Edit StackSet details** option. You must use the **Override StackSet parameters**. For more information on overriding parameters, see [Override parameters on stacks](stackinstances-override.md).
+ The StackSets quotas and stack instances apply when importing stacks. For more information about quotas, see [Understand CloudFormation quotas](cloudformation-limits.md).

**Topics**
+ [Self-managed stack import for CloudFormation StackSets](self-managed-import.md)
+ [Service-managed stack import for CloudFormation StackSets](service-managed-import.md)
+ [Revert stack imports into CloudFormation StackSets](revert-stackset-import.md)