AWS RDS Reserved Instances Migration from Intel to Graviton based Processors or vice versa

Hello, please see our documentation here: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithReservedDBInstances.html

The new DB instance that you create must match the specifications of the reserved DB instance—same DB engine, DB instance type, license type (license-included or bring-your-own-license), edition (for RDS for Oracle and RDS for SQL Server), and AWS Region.

If the specifications of the new DB instance match an existing reserved DB instance for your account, you are billed at the discounted rate offered for the reserved DB instance. Otherwise, the DB instance is billed at an on-demand rate.

You can modify a DB instance that you're using as a reserved DB instance. If the modification is within the specifications of the reserved DB instance, part or all of the discount still applies to the modified DB instance. If the modification is outside the specifications, such as changing the instance class, the discount no longer applies. For more information, see Size-flexible reserved DB instances.

Now you may be able to "exchange" the instances depending on how many are moving to graviton or intel based instance.

If you delete a DB instance that is covered by a reserved DB instance discount, you can launch another DB instance with compatible specifications. In this case, you continue to get the discounted rate during the reservation term (one or three years).

Hope it helps,

Jon