Summary
Anthropic retires older Claude models on a regular cadence as safer, more capable models launch. This page defines the lifecycle vocabulary (active, legacy, deprecated, retired), the notification and migration obligations attached to each stage, the current status of each API model name, and a chronological history of deprecation announcements with recommended replacements. Applications that hard-code model IDs will eventually break unless they migrate before the retirement date.
Key Points
- Four lifecycle states: Active (fully supported), Legacy (no further updates, may be deprecated), Deprecated (functional but discouraged; replacement assigned and retirement date published), Retired (unavailable — requests fail).
- Deprecated models are likely to be less reliable than active models; workloads should move to active models to keep the highest level of support.
- Anthropic gives at least 60 days' notice before retiring a publicly released model, via email to customers with active deployments plus documentation.
- Lifecycle dates on this page apply only to Anthropic-operated platforms (Claude API, Claude Platform on AWS, Google Cloud Anthropic-managed, Microsoft Foundry). Amazon Bedrock and Google-managed Cloud models retire on their own schedules and may not match.
- Usage can be audited via Console → Usage → Export, which yields a CSV broken down by API key and model — useful for finding lingering deprecated references.
- Retirement exists partly to free capacity for new releases, but carries acknowledged downsides: forced migration, loss of access for researchers doing longitudinal/comparative studies, and safety/model-welfare risks. Anthropic commits to long-term weight preservation and hopes to re-release past models publicly someday.
- Beyond whole models, API request parameters are also deprecated:
temperature,top_p, andtop_kare removed in API version 2026-10-21 (returns HTTP 400); guiding behavior via prompting replaces them.