The identifier in your request is the default
A request here names the model identifier it wants, so the platform has no default to publish. The effective one is whatever a customer's code has been saying since somebody wrote it, and the lifecycle state on that model is what tells them when the string needs to change. As of 2026-09-22.
| What the page is asked | What Amazon Bedrock publishes | What that leaves open |
|---|---|---|
| Is a starting tier stated | Not applicable, a request names the identifier | The platform never chooses for you |
| Where the effective default lives | In the customer's own code or configuration | Unchanged until somebody edits it |
| What signals that it should change | The lifecycle state on that model | Readable through the interface itself |
| Who performs the change | Migration will not happen automatically | Stated plainly on the lifecycle page |
Inclusion rule. Filled when the entry's own public page says which model a new project starts on, or when a single-model menu makes the answer follow from the list having one line. Order. What does not apply first, then where the default actually sits.
1A default that nobody published still exists
The platform does not choose an engine, and yet almost every caller has one it uses without thinking, because a string written eighteen months ago is still in the code. That is a default in every practical sense and it belongs to the customer.
This column records the platform's answer and names the real location of the risk. A production that has never audited which identifiers its own tooling sends is in the same position as one on an unnamed tier.
2The state is the reminder the code cannot give itself
What makes this arrangement better than an unnamed tier is that the model carries a readable state. A caller can check it on a schedule and learn that its long-standing string is now in a legacy window.
Without that, an aging identifier is invisible until it fails. With it, the audit is automatable, which is the difference between a migration that is planned and one that is discovered.
3Nobody moves the string for you
The lifecycle page says migration will not happen automatically, so the edit is the customer's work and so is choosing what to edit it to. No successor is named for any model.
Both halves are recorded in the succession reading. The platform is unusually clear that this is your job, which is more useful than leaving it implied.
- The three states a model can be inActive, Legacy or End-of-Life, readable from the modelLifecycle field
- Whether the platform moves you acrossMigration will not happen automatically
4Sources
Read from the model lifecycle page on docs.aws.amazon.com, 2026-09-22. The whole entry is on Amazon Bedrock, and the column it sits in is on Default tier. Same column, other entries: Gemini API, Wan-AI.