Amazon Bedrock's model lifecycle page lists Anthropic's Claude Sonnet 4.5 (anthropic.claude-sonnet-4-5-20250929-v1:0) among Legacy models, with an end-of-life (EOL) date of April 8, 2027. Amazon says that on or soon after that date "requests made to this version will fail", unless there is a private arrangement between the customer and the provider for continued access.
The dates
Amazon's table gives three dates, with no time zone:
- October 8, 2026: Legacy date. It has passed; the page does not say when the row was added.
- January 8, 2027: public extended access start date.
- April 8, 2027: EOL date.
The row lists 31 Regions, by this desk's count. Its Bedrock model card shows Legacy and the same EOL date.
What changes
Legacy. Amazon says new customers can't use Legacy models, and existing customers may lose access after 15 days of inactivity.
From January 8. Active users can keep using the model until the EOL date, but Amazon says to expect higher pricing, set by the model provider; elsewhere the page says pricing "may increase". The page gives no Sonnet 4.5 price.
Before April 8. Amazon says customers will need to migrate to the latest model by updating their application code before the EOL date, and that migration will not happen automatically. The table has no replacement column and names no replacement model.
Check your Region
Amazon says lifecycle state can differ by Region. The Regions column lists only the Regions covered by the announced EOL date. A model can remain Active elsewhere, and a missing Region does not mean the model stays available there indefinitely. To check, Amazon says to call ListFoundationModels or GetFoundationModel in your Region.
Price, and Anthropic's own dates
On Bedrock's pricing page as served on October 10, the "Models with extended access" table lists Claude 3.5 Sonnet and Claude 3.5 Sonnet v2, not Sonnet 4.5. Sonnet 4.5's own rows fill in their prices by script, so the page as served shows no dollar figure for them. That is a reading of the page, not a finding that no extended-access price exists.
Anthropic's model deprecations page lists claude-sonnet-4-5-20250929 as Deprecated, with a deprecation date of September 30, 2026, a tentative retirement date of November 30, 2026, and claude-sonnet-5-5 as the recommended replacement. It says its dates apply to Anthropic-operated platforms (the Claude API, Claude Platform on AWS and Microsoft Foundry) and that partner-operated platforms, including Amazon Bedrock, set their own retirement schedules. Amazon's page says only its dates apply on Bedrock, so the two are not combined.
Disclosure: Hugin's records are drafted with the help of Claude models made by Anthropic.