We are announcing the end of support for selected AI models on the Standard and GitHub Copilot harnesses in Copilot Studio. Beginning on each models’ applicable migration date, the selected models will no longer be available in Copilot Studio, and agents will automatically migrate to a replacement model.
Message ID: MC1506318
Published: Oct 13, 2026
Service: Microsoft Copilot (Power Platform)
Tag: Retirement
How does this affect me?
Agents configured with retiring models will be automatically migrated to a supported replacement model. The planned replacement model and migration date depends on both the model and the harness used by the agent.
Review your agents by harness and model to identify those using a retiring model, then work with their owners to prepare for migration.
For the latest model availability, see the guidance for your agent’s harness:
- Standard harness model availability
- GitHub Copilot harness model availability
| Retiring model | Harness | Planned replacement model | Migration date |
|---|---|---|---|
| GPT-4.1* | Standard | GPT Chat Latest | November 12, 2026 |
| GPT-4.1 Mini | Standard | GPT Chat Latest | November 12, 2026 |
| GPT-5 Chat* | Standard | GPT Chat Latest | November 12, 2026 |
| GPT-5 Chat* | GitHub Copilot | GPT 5.6 Terra | November 12, 2026 |
| GPT-5 Auto | Standard | GPT Chat Latest | November 12, 2026 |
| GPT-5 Reasoning | Standard | GPT Chat Latest | November 12, 2026 |
| GPT 5.6 Sol | GitHub Copilot | GPT 6 Sol | November 12, 2026 |
| GPT 5.6 Luna | GitHub Copilot | GPT 6 Luna | November 12, 2026 |
*Note: For U.S.-based tenants with cross-geo data movement enabled, GPT-4.1 and GPT-5 will remain supported and will not retire as part of this migration. To learn more about cross-geo data movement, including availability and eligibility, see Geographical availability of Copilot.
GPT Chat Latest is the supported chat model option going forward for the Copilot Studio Standard harness. It keeps agents on the latest supported GPT chat model as snapshots within the current major model version are updated over time. Moving to a new major model version is a separate change, and customers will receive at least 30 days’ notice.
For agents on the GitHub Copilot harness, refer to the planned replacement model listed in the table above.
Choose the model that best fits your agent
You can use the planned replacement or choose a supported model that better meets your agent’s quality, performance, or cost needs.
Model availability depends on your harness, region, and administrator settings. Use the guidance for your agent’s harness:
- Standard harness
- GitHub Copilot harness
Please test your agent on the model you choose before migration begins.
What action do I need to take?
Before the migration date for each retiring model, we recommend admins and makers take the following actions:
- Identify affected agents in the Power Platform admin center by going to Manage > Copilot Studio and reviewing agents by harness and model.
- The model field is currently in preview. The inventory reflects published agent configurations, so unpublished model changes might not appear. See the admin agent inventory for details.
- Notify the appropriate agent owners.
- Test the planned replacement model, or choose another supported model that better meets quality, performance, or cost requirements.
- Validate response accuracy, key workflows, tool and action execution, and business-critical integrations.
- Adjust agent instructions or configuration if testing identifies behavior changes.
- Review model availability, regional availability, and any cross-geo or external model-provider requirements.
We will send an announcement with retirement dates for older versions of the Claude Opus and Claude Sonnet models. In the GitHub Copilot harness, Opus 5.5 and Sonnet 5.5 are already available for your agents.
For more information, please visit:
- Test your agent
- Copilot Studio model lifecycle guidance
- Chat Latest Model | OpenAI API