Google restricts Gemini 2.5 API access to accounts with prior usage, keeps models served

Google updated its Gemini API changelog on September 18, 2026 to announce that access to its Gemini 2.5 model family is now limited to developers who have previously used those models, while stopping short of deprecating them.

What's new

The changelog entry reads: "To ensure reliable performance for everyone, we are limiting access to the 2.5 models to users who have actively used them in the past. These models are not deprecated and will continue to be served until further notice through the API."

The move ties ongoing access to prior usage rather than setting a hard cutoff date. Developers or accounts that haven't called a Gemini 2.5 model before this change will not be able to start using it now, even though existing users can keep relying on it indefinitely, "until further notice."

Context

Gemini 2.5 has been superseded in Google's lineup by the Gemini 3.x series, including Gemini 3.6 Flash and Gemini 3.5 Flash-Lite, which Google brought to general availability earlier this month. Rather than issuing a traditional deprecation notice with a shutdown date, Google is using an access-gating approach: existing 2.5 workloads keep running, but the door closes on new adoption. Google frames the change as being about "reliable performance for everyone," suggesting the restriction is intended to manage serving capacity for a model generation it is no longer promoting to new users.

Why it matters

This is a notable departure from a standard deprecation-with-shutdown-date lifecycle, and it sets a precedent worth watching: rather than forcing every customer off an older model on a fixed timeline, Google is grandfathering existing users while quietly closing new access. For developers currently building on Gemini 2.5, nothing breaks today. For anyone who hasn't yet integrated it, the model is effectively already unavailable, pushing new integrations toward the Gemini 3.x line by default.