Quick answer: On June 15, Anthropic retires Claude 4 Opus and Claude Sonnet 4. If your app pins either model by ID, you need to switch before that date. The replacements are newer, and in the case of Opus, meaningfully cheaper.
What changes
Two models reach end of life on June 15:
- Claude 4 Opus is replaced by Claude Opus 4.7 / 4.8. According to current pricing reports, the newer Opus lists at roughly $5 / $25 per million tokens (input / output) versus $15 / $75 for Claude 4 Opus — about 67% lower on list price. Confirm the exact figures against Anthropic's official pricing before you budget.
- Claude Sonnet 4 is replaced by Claude Sonnet 4.6 — same price point, better quality, and a 1M-token context window.
June 15 is also the date of Anthropic's previously announced Claude subscription change, so it is worth treating the whole week as a migration window rather than a single switch.
Migration checklist
If you build directly on Claude, the move is small but time-boxed:
- Find every hard-coded model ID (
claude-opus-4,claude-sonnet-4) across your app, SDK config, and environment variables. - Repoint defaults to Opus 4.7/4.8 and Sonnet 4.6.
- Run your eval suite on the new models before flipping production — quality and tokenization can shift between versions.
- Update cost configuration to benefit from the lower Opus pricing, and revisit any prompt that was trimmed to fit context now that Sonnet 4.6 offers 1M tokens.
Why this is an argument for provider abstraction
A forced model retirement on a fixed date is exactly the kind of event a single-provider architecture turns into a fire drill. With a multi-provider setup, swapping one model ID for another is a config change, not a rewrite — and the same indirection lets you route to a cheaper or longer-context model the moment it ships. The migration is easy this time. The lesson is to make it easy every time.