Claude Sonnet 4.5 scheduled for retirement

Verification is under 30 days old, not a live check; date passage does not confirm shutdown.

What changed

Impact summary

Anthropic deprecated Claude Sonnet 4.5 on Sep 30, 2026 and lists retirement on Nov 30, 2026 with replacement claude-sonnet-5-5.

BeforeActive (earliest retirement not sooner than September 29, 2026)

After / replacementclaude-sonnet-5-5

claude-sonnet-4-5-20250929

Recommended next step: Migrate from claude-sonnet-4-5-20250929 to claude-sonnet-5-5 before 2026-11-30. Requests after retirement fail.

API platform & regional scope

Anthropic Claude API · Direct developer platform; eligibility and regional restrictions are account-specific.

Not Bedrock / Vertex partner copies unless separately documented.

Reviewed merge · 2026-10-13.

Unconfirmed regions are not assumed to be global. Scheduled checks cover only sources in the current monitored list. Source checks

Deprecation September 30, 2026; retirement November 30, 2026; replacement claude-sonnet-5-5. Partner platforms may differ.

Action / deadline: Review required · Stated deadline

This record is classified as official announcement. The facts above were normalized from the provider's public developer documentation.