Amazon RDS for PostgreSQL is announcing deprecation of its PostgreSQL major version 10, starting April 17, 2023. PostgreSQL community plans to deprecate PostgreSQL 10 on November 10, 2022  and it will not receive any security patches after November 10, 2022. We strongly recommend that you monitor the PostgreSQL security page for documented vulnerabilities .
We recommend that you take action and upgrade your PostgreSQL databases running on major version 10 to a later major version, such as version 14. PostgreSQL 14 includes performance improvements for parallel queries, heavily-concurrent workloads, partitioned tables, logical replication, and vacuuming. To learn more about the benefits of PostgreSQL 14, please refer to ‘PostgreSQL 14 Community Release Announcement’ 
To upgrade your DB instance from major version 10, we recommend that you first upgrade your current version of database to a minor version such as 10.19 or later that has an upgrade path to the target major version, and then perform an upgrade to a later major version, such as 14. You can initiate an upgrade by going to the Modify DB Instance page in the AWS Management Console and change the database version setting to a newer major version of PostgreSQL. Alternatively, you can also use the AWS CLI to perform the upgrade. While major version upgrades typically complete within the standard maintenance window, the duration of the upgrade depends on the number of objects within the database. To avoid any unplanned unavailability outside your maintenance window, we recommend that you first take a snapshot of your database and test the upgrade to get an estimate of the upgrade duration. To learn more about upgrading PostgreSQL major versions in RDS, review the 'Upgrading Database Versions' page .
The upgrade process will shutdown the database instance, perform the upgrade, and restart the database instance. The DB instance may restart multiple times during the process. If you choose the "Apply Immediately" option, the upgrade will be initiated immediately after clicking on the "Modify DB Instance" button. If you choose not to apply the change immediately, the upgrade will be performed during your next maintenance window.
Your affected Amazon RDS DB Instances are listed in "Affected Resources" tab of the AWS Health Dashboard.
Starting February 14, 2023 00:00:01 AM UTC, you will not be able to create new RDS instances with PostgreSQL major version 10 from either the AWS Console or the CLI. We recommend you to upgrade your databases before April 17, 2023. RDS will upgrade your PostgreSQL 10 databases to PostgreSQL 14 during a scheduled maintenance window between April 17, 2023 00:00:01 UTC and July 18, 2023 00:00:01 UTC. On July 18, 2023 00:00:01 AM UTC, any PostgreSQL 10 databases that remain will be force upgraded to version 14 regardless of instances’ scheduled maintenance window.
If you have any questions or concerns, please reach out to AWS Support . To proactively plan for future PostgreSQL deprecation of major version 11 and above, you can now refer to published RDS for PostgreSQL deprecation dates here