# Migrating off claude-3-sonnet-20240229

**Anthropic** retires **claude-3-sonnet-20240229** on **2025-07-21**.
Documented replacement: **claude-sonnet-4-6**.

Source: https://docs.anthropic.com/en/docs/about-claude/model-deprecations
Source check date not recorded.
Calendar as of 2026-09-15 UTC.

| Model | Provider | Retires | Replacement |
|---|---|---|---|
| claude-3-sonnet-20240229 | Anthropic | 2025-07-21 | claude-sonnet-4-6 |

Also retiring on 2025-07-21:
- claude-2.0 (Anthropic) → claude-opus-4-8
- claude-2.1 (Anthropic) → claude-opus-4-8

Source: https://llmlatency.dev/migrate/anthropic-claude-3-sonnet-20240229