# Add stacks to CloudFormation StackSets
<a name="stackinstances-create"></a>

When you create a StackSet, you can create the stacks for that StackSet. CloudFormation also enables you to add more stacks, for additional accounts and Regions, at any point after the StackSet is created. You can add stacks using either the CloudFormation console or the AWS CLI.

**Topics**
+ [Add stacks to a StackSet (console)](#stackinstances-create-console)
+ [Add stacks to a StackSet (AWS CLI)](#stackinstances-create-cli)

## Add stacks to a StackSet (console)
<a name="stackinstances-create-console"></a>

**To add stacks to a StackSet**

1. Sign in to the AWS Management Console and open the CloudFormation console at [https://console.aws.amazon.com/cloudformation](https://console.aws.amazon.com/cloudformation/).

1. On the navigation bar at the top of the screen, choose the AWS Region you created the StackSet in.

1. From the navigation pane, choose **StackSets**. On the StackSets page, select the StackSet that you created.

1. With the StackSet selected, choose **Add stacks to StackSet** from the **Actions** menu.

1. On the **Set deployment options** page, do the following:

   1. For **Add stacks to StackSet**, choose **Deploy new stacks**.

   1. Next, do the following depending on your StackSet's permissions configuration:
      + [Self-managed permissions] For **Accounts**, **Deployment locations**, choose **Deploy stacks in accounts**. Paste your target account numbers in the text box, separating multiple numbers with commas.
      + [Service-managed permissions] For **Deployment targets**, do one of the following:
        + Choose **Deploy to organization** to deploy to all accounts in your organization.
        + Choose **Deploy to organizational units (OUs)** to deploy to all accounts in specific OUs. Choose **Add another OU**, and then paste the target OU ID in the text box. Repeat for each new target OU. CloudFormation also targets any child OUs of your selected targets.
**Note**  
If you add an OU that your StackSet already targets, CloudFormation creates new stacks in any accounts in the OU that don't already have stacks from your StackSet (for example, accounts that were added to the OU after your StackSet was created and with automatic deployments disabled).

   1. For **Specify regions**, specify which AWS Regions to deploy to in the target accounts you specified in the previous step. By default, CloudFormation will deploy stacks in the specified accounts within the first Region, then moves on to the next, and so on, as long as a Region's deployment failures don't exceed a specified failure tolerance.

   1. For **Deployment options**, do the following:
      + For **Maximum concurrent accounts**, specify how many accounts are processed concurrently.
      + For **Failure tolerance**, specify the maximum number of account failures allowed per Region. The operation will stop and won't proceed to other Regions once this limit is reached.
      + For **Region concurrency**, choose how to process Regions: **Sequential** (one Region at a time) or **Parallel** (multiple Regions concurrently).
      + For **Concurrency mode**, choose how concurrency behaves during operation execution.
        + **Strict failure tolerance** – Reduces account concurrency level when failures occur, staying within **Failure tolerance** \$11.
        + **Soft failure tolerance** – Maintains your specified concurrency level (the value of **Maximum concurrent accounts**) regardless of failures. 

   1. Choose **Next**.

1. On the **Specify Overrides** page, leave the property values as specified. You won't be overriding any property values for the stacks you're going to create. Choose **Next**.

1. On the **Review** page, review your choices. To make changes, choose **Edit** on the related section.

1. When you're ready to proceed, choose **Submit**.

   CloudFormation starts creating your stacks. View the progress and status of the creation of the stacks in your StackSet in the StackSet details page that opens when you choose **Submit**. When complete, your new stacks should be listed on the **Stack instances** tab.

## Add stacks to a StackSet (AWS CLI)
<a name="stackinstances-create-cli"></a>

**Note**  
When acting as a delegated administrator, you must include `--call-as DELEGATED_ADMIN` in the command. 

**To add stacks to a StackSet with self-managed permissions**  
Use the **create-stack-instances** CLI command. For the `--accounts` option, provide the accounts IDs for which you want to create stacks.

```
aws cloudformation create-stack-instances --stack-set-name my-stackset \
  --accounts account_id --regions eu-west-1 us-west-2
```

**To add stacks to a StackSet with service-managed permissions**  
Use the **create-stack-instances** CLI command. For the `--deployment-targets` option, provide the organization (root) ID or OU IDs for which you want to create stacks. For example commands that target specific accounts, see [Create a StackSet with service-managed permissions (AWS CLI)](stacksets-orgs-associate-stackset-with-org.md#stacksets-orgs-associate-stackset-with-org-cli).

```
aws cloudformation create-stack-instances --stack-set-name my-stackset \
  --deployment-targets OrganizationalUnitIds=ou-rcuk-r1qi0wl7 --regions eu-west-1 us-west-2
```

**Note**  
If you add an OU that your StackSet already targets, CloudFormation creates new stacks in any accounts in the OU that don't already have stacks from your StackSet (for example, accounts that were added to the OU after your StackSet was created and with automatic deployments disabled).