Long-Term Support Program Launch

GitHub has established a new commitment to enterprise stability by introducing long-term support (LTS) models for Copilot Business and Copilot Enterprise users. Under this program, designated LTS models will remain available for a full 12 months from their launch date, enabling enterprises to conduct thorough internal security and safety reviews without worrying about rapid model deprecation.

GPT-5.3-Codex: First LTS Model

GPT-5.3-Codex is GitHub's first LTS model, developed in partnership with OpenAI. The model launched on February 5, 2026, and will be supported through February 4, 2027 for Copilot Business and Enterprise users. GitHub reports that GPT-5.3-Codex demonstrates a significantly high code survival rate among enterprise customers, indicating strong code quality and reliability for production environments.

Base Model Migration Timeline

GPT-5.3-Codex will also serve as the newest base model for Copilot, replacing GPT-4.1. The base model is used by default when organizations haven't approved other models through their internal review process. GitHub will automatically enable GPT-5.3-Codex for all Copilot Business and Enterprise organizations within 60 days of this announcement (by May 17, 2026).

Pricing: GPT-5.3-Codex carries a 1x premium request unit multiplier, meaning it will consume standard request units. GPT-4.1 will remain force-enabled at a 0x multiplier to ensure no disruption during the transition period.

Key Dates and Scope

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

Important: These changes apply only to Copilot Business and Copilot Enterprise plans. Copilot Pro, Copilot Pro+, and Copilot Free plans follow standard model deprecation timelines.

Action Items

Organizations that need more time to prepare for the transition or have questions should contact their GitHub account team. Additional information is available in GitHub's documentation on supported models and model management policies.