Official Patch Notes

As announced on March 18, 2026, GPT-5.3-Codex is now the base model for all Copilot Business and Copilot Enterprise organizations, replacing GPT-4.1. The base model is used when your organization hasn’t yet approved other models through its internal review process. GPT-5.3-Codex is also our first long-term support (LTS) model, in partnership with OpenAI. LTS models are guaranteed to be available for a full 12 months from the model’s launch date, giving enterprises the stability they need for internal security and safety reviews. GPT-5.3-Codex launched on February 5, 2026 and will remain available through February 4, 2027 for Copilot Business and Copilot Enterprise users. GitHub Copilot data has shown that GPT-5.3-Codex has a significantly high code survival rate among enterprise customers. Premium request multipliers GPT-5.3-Codex carries a 1x premium request unit multiplier. GPT-4.1 will remain force-enabled at a 0x multiplier for the time being, though it will deprecate alongside the launch of usage-based billing on June 1, 2026 . If your team has questions or needs more time, contact your account team. Key dates March 18, 2026: LTS and base model changes announced. May 17, 2026: GPT-5.3-Codex becomes the base model for all Copilot Business and Copilot Enterprise organizations. February 4, 2027: End of the LTS availability window for GPT-5.3-Codex. Who this applies to These changes apply to Copilot Business and Copilot Enterprise plans only. They don’t apply to Copilot Pro, Copilot Pro+, or Copilot Free. On individual plans, model deprecation will follow the standard timeline. Learn more in our docs about supported models and our model management documentation in GitHub Copilot. The post GPT-5.3-Codex is now the base model for Copilot Business and Enterprise appeared first on The GitHub Blog .

As announced on March 18, 2026, GPT-5.3-Codex is now the base model for all Copilot Business and Copilot Enterprise organizations, replacing GPT-4.1. The base model is used when your organization hasn’t yet approved other models through its internal review process.

GPT-5.3-Codex is also our first long-term support (LTS) model, in partnership with OpenAI. LTS models are guaranteed to be available for a full 12 months from the model’s launch date, giving enterprises the stability they need for internal security and safety reviews. GPT-5.3-Codex launched on February 5, 2026 and will remain available through February 4, 2027 for Copilot Business and Copilot Enterprise users.

GitHub Copilot data has shown that GPT-5.3-Codex has a significantly high code survival rate among enterprise customers.

Premium request multipliers GPT-5.3-Codex carries a 1x premium request unit multiplier. GPT-4.1 will remain force-enabled at a 0x multiplier for the time being, though it will deprecate alongside the launch of usage-based billing on June 1, 2026 .

If your team has questions or needs more time, contact your account team.

Key dates

March 18, 2026: LTS and base model changes announced. May 17, 2026: GPT-5.3-Codex becomes the base model for all Copilot Business and Copilot Enterprise organizations. February 4, 2027: End of the LTS availability window for GPT-5.3-Codex.

Who this applies to These changes apply to Copilot Business and Copilot Enterprise plans only. They don’t apply to Copilot Pro, Copilot Pro+, or Copilot Free. On individual plans, model deprecation will follow the standard timeline.

Learn more in our docs about supported models and our model management documentation in GitHub Copilot.

The post GPT-5.3-Codex is now the base model for Copilot Business and Enterprise appeared first on The GitHub Blog .