AWS Mainframe Modernization Service (Managed Runtime Environment experience) is no longer open to new customers. For capabilities similar to AWS Mainframe Modernization Service (Managed Runtime Environment experience) explore AWS Mainframe Modernization Service (Self-Managed Experience). Existing customers can continue to use the service as normal. For more information, see [AWS Mainframe Modernization availability change](https://docs.aws.amazon.com/m2/latest/userguide/mainframe-modernization-availability-change.html).

# Update an AWS Mainframe Modernization application
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Use the AWS Mainframe Modernization console to update an AWS Mainframe Modernization application. Updating an application creates a new version of the application.

These instructions assume that you have completed the steps in [Set up for AWS Mainframe Modernization](setting-up.md).

## Update an application
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An AWS Mainframe Modernization application can have multiple versions, each with its own application definition. To update an application, provide a new application definition. This creates a new version of the application.

**To update an application**

1. Open the AWS Mainframe Modernization console at [https://console.aws.amazon.com/m2/](https://console.aws.amazon.com/m2/).

1. In the AWS Region selector, choose the Region where the application that you want to update was created.

1. On the **Applications** page, choose the application that you want to update.

1. On the application details page, in the **Current definition** section, choose **Edit** to update the current application definition.

1. On the **Update application** page, use the inline editor to update the current application definition.

    Alternatively, choose **Use an application definition JSON file in an Amazon S3 bucket** and provide the location of the application definition that you want to use. For more information, see [AWS Transform for mainframe application definition sample](applications-m2-definition.md#applications-m2-definition-ba) or [Rocket Software (formerly Micro Focus) application definition](applications-m2-definition.md#applications-m2-definition-mf).

1. When you're finished updating the application definition, choose **Update**.

**Note**  
After you update the application, you must deploy it again. For more information, see [Deploy an AWS Mainframe Modernization application](applications-m2-deploy.md).