We announced the deprecation of the Claude Sonnet 4.5 model retirement date and replacement

Name: We announced the deprecation of the Claude Sonnet 4.5 model retires (Anthropic)
Start: 2026-11-30
End: 2026-11-30

Anthropic · Model · retires Nov 30, 2026 (in 56 days)Unverified

Dates

Checked Oct 5, 2026 on Anthropic's page

Retires	Nov 30, 2026 (in 56 days)
Announced	Sep 30, 2026
Replacement	None named
Notice	We announced the deprecation of the Claude Sonnet 4.5 model (claude-sonnet-4-5-20250929), with retirement on the Claude API scheduled for November 30, 2026.
Source	platform.claude.com/docs/en/release-notes/overview#september-30-2026

Announced
Oct 5today
Retires Nov 30, 2026. We announced the deprecation of the Claude Sonnet 4.5 model (claude-sonnet-4-5-20250929), with retirement on the Claude API scheduled for November 30, 2026.

Date	Change	Source
Oct 5today	Announced2026-11-30UnverifiedWe announced the deprecation of the Claude Sonnet 4.5 model (claude-sonnet-4-5-20250929), with retirement on the Claude API scheduled for November 30, 2026.Source	Source