Rapid-response update — this article reflects the situation as of June 18, 2026 and may change. The June 22 change to the consumer Claude apps is attributed to Anthropic's in-app notice; the developer-API lifecycle details are attributed to Anthropic's official model deprecations documentation.
Per Anthropic's in-app notice, Claude Sonnet 4.5 is being removed from the model picker in the consumer Claude apps — Claude chat and Claude Cowork — on June 22, 2026. Existing and in-progress chats keep working, and you can switch to a newer model (Anthropic recommends Sonnet 4.6) at any time, even mid-chat. No other action is required beyond selecting a current model going forward. This is a different lifecycle from the developer API: on the Claude API, the model identifier claude-sonnet-4-5-20250929 is still active, with a tentative retirement date listed as "not sooner than September 29, 2026" on Anthropic's official model deprecations page. If you only use the Claude apps, just pick a current model. If you build on the Claude API, you have until at least late September 2026 — but you should plan a tested migration now.
claude-sonnet-4-5-20250929 is still active, with a tentative retirement listed as not sooner than September 29, 2026 on Anthropic's official deprecations page. The API, Claude Platform on AWS, and Microsoft Foundry follow their own schedules — they are not governed by the consumer-app picker change.claude-sonnet-4-5-20250929 is pinned and plan a tested migration before your platform's retirement window.According to Anthropic's in-app notice, Claude Sonnet 4.5 will be removed from the model picker in the consumer Claude apps — Claude chat and Claude Cowork — on June 22, 2026. The practical details, per that notice:
This is a routine model-lifecycle event. We are reporting the June 22 picker change as described in Anthropic's in-app notice. As of this writing, we did not find an official Anthropic newsroom post stating the June 22 date, so we attribute it to the in-app notice and do not rely on unofficial commentary. We also take no position on model-quality comparisons between versions — that is not what this change is about.
The single most important thing to understand is that "Sonnet 4.5 is being retired" means two different things depending on where you use it. Treating them as one will mislead developers into thinking an API outage is imminent when it is not.
| Surface | What is happening | Effective date | Action needed |
|---|---|---|---|
| Consumer Claude apps (Claude chat, Claude Cowork) | Sonnet 4.5 removed from the model picker; existing chats keep working | June 22, 2026 (per Anthropic in-app notice) | Pick a newer model (Sonnet 4.6); can switch mid-chat |
Claude API (claude-sonnet-4-5-20250929) |
Model is still active; deprecation tracked on Anthropic's official page | Not sooner than September 29, 2026 (tentative) | Plan and test a migration before the window; no June 22 impact |
| Claude Platform on AWS, Microsoft Foundry, and other partner platforms | Governed by Anthropic's deprecation policy for operated platforms and each partner's own schedule | Set per platform | Confirm your platform's specific dates |
The June 22 picker removal applies only to the consumer-app experience. It does not shut off the API model, and it does not affect builders running Claude through the API, AWS, or other partner platforms.
| Group | Effect |
|---|---|
| Claude chat / Claude Cowork users | On June 22, 2026, Sonnet 4.5 disappears from the picker. Existing chats continue; choose Sonnet 4.6 (or another current model) for new work. |
Claude API builders (claude-sonnet-4-5-20250929) |
Not affected on June 22. The model stays active until at least late September 2026 (tentative). Plan a migration; no emergency. |
| Teams on Claude via AWS or Microsoft Foundry | Follow each platform's own retirement schedule. Confirm dates with the platform; not governed by the app picker. |
| Teams using Claude inside Salesforce / Agentforce or HubSpot workflows | Depends on how Claude is invoked. App-based usage follows the picker change; API/connector-based usage follows the API lifecycle. Confirm which path your automations use. |
The takeaway: if your Claude usage is through the apps, June 22 matters and the fix is a single click. If your usage is through the API or a partner platform, June 22 is a non-event — but a model migration is on your horizon and deserves a tested plan.
claude-sonnet-4-5-20250929. Check identifiers, not just product names.| Date | Event |
|---|---|
| September 29, 2025 | Sonnet 4.5 (claude-sonnet-4-5-20250929) released on the Claude API. |
| June 18, 2026 | This rapid-response summary published. |
| June 22, 2026 | Sonnet 4.5 removed from the model picker in Claude chat and Claude Cowork (per Anthropic in-app notice). Existing chats keep working. |
| Not sooner than September 29, 2026 (tentative) | Earliest possible retirement of claude-sonnet-4-5-20250929 on the Claude API, per Anthropic's deprecations page. Partner platforms set their own dates. |
This timeline reflects the information available as of June 18, 2026 and may be updated. The API retirement date is explicitly tentative.
Model retirements are not crises — they are routine. New versions ship, older ones sunset, and the cadence is only accelerating. The teams that handle this calmly are the ones that designed for it. The teams that scramble are the ones that hard-coded a single model into a dozen workflows.
A model-version-resilient AI operating model assumes any single version may change:
For a closer look at how model events play out in practice, see our coverage of the Claude Fable 5 and Mythos 5 suspension and our model-selection breakdown in Claude Fable 5 vs Opus 4.8. For builders weighing API-side changes, our analysis of the Claude Agent SDK billing splits covers the same discipline applied to billing and architecture.
Vantage Point's approach is vendor-agnostic and dual-platform across Salesforce and HubSpot, staffed only by senior consultants, and built to integrate with the systems you already run — which is exactly what makes a version-resilient, configuration-driven design practical to implement and maintain.
Vantage Point is a Registered Claude Partner Network member (confirmed June 2026), and we are an employee-owned, mid-market specialist staffed only by senior consultants. We do not claim certifications, and we do not take positions on model-quality debates.
What we do is turn routine model events into operational resilience. A typical Claude/AI advisory engagement maps where Claude is used across your apps, API, and partner platforms; standardizes your team on current models; abstracts model identifiers so future swaps are configuration changes; builds a repeatable migration-and-testing routine; and documents the governance to keep it all compliant. Strategy and rollout run through advisory and change management; the connective work of wiring Claude resiliently into your stack runs through system integration and data migration; and the workflow design that ties Claude to real outcomes runs through AI-driven personalization and analytics. Every engagement is senior-staffed and works across both Salesforce and HubSpot.
Ready to make your Claude workflows version-resilient? Book a Claude / AI advisory consultation with Vantage Point and we will help you standardize on current Claude models, abstract model choices, and build a migration habit that turns every future retirement into a non-event.
No. Per Anthropic's in-app notice, June 22 only removes Sonnet 4.5 from the model picker in the consumer Claude apps (Claude chat and Claude Cowork). On the developer side, the API model claude-sonnet-4-5-20250929 remains active, with a tentative retirement listed as not sooner than September 29, 2026 on Anthropic's official deprecations page.
Just pick a newer model. Anthropic recommends Sonnet 4.6. Existing and in-progress chats keep working, and you can switch models at any time, even in the middle of a conversation. No other action is needed.
No. The June 22 change does not affect the API. Your claude-sonnet-4-5-20250929 calls keep working. You should, however, inventory where that model is pinned and plan a tested migration before your platform's retirement window — for the Claude API, that is tentatively not sooner than September 29, 2026.
Those partner platforms follow Anthropic's deprecation policy for operated platforms plus their own schedules. They are not governed by the consumer-app picker change. Confirm the specific retirement date with your platform, and check Anthropic's official model deprecations page for the authoritative API-side lifecycle.
Per Anthropic's own guidance, Sonnet 4.6 is the recommended replacement in the consumer apps. For API workloads, validate the newer model against your prompts, output quality, cost, and latency before switching in production.
It depends on how Claude is invoked. If your team uses the Claude apps directly, the picker change applies. If your automations call Claude through the API or a connector, the API lifecycle applies instead. Confirm which path each workflow uses, and review any middleware that selects models indirectly.
Because they are — new model versions ship and older ones sunset on a regular cadence. The risk is not any single retirement; it is building mission-critical workflows on a single hard-coded model with no migration plan. A version-resilient design makes each retirement a configuration change rather than a fire drill.
As a Registered Claude Partner Network member, we help mid-market teams standardize on current Claude models, abstract model identifiers into configuration, build a repeatable migration-and-testing routine, and document governance — across both Salesforce and HubSpot. Start with a Claude / AI advisory consultation.
This is a rapid-response update as of June 18, 2026. The June 22 consumer-app change is attributed to Anthropic's in-app notice; verify the developer-API lifecycle against Anthropic's official model deprecations page before acting, and treat the details above as reflecting that point in time.