Answer generation model versions and lifecycle Stay organized with collections Save and categorize content based on your preferences.
Vertex AI Search offers multiple model versions for you to choose when generating answers. You can choose the model versions when using search summaries and answers and follow-ups.
Available models
Vertex AI Search uses two types of models for question and answering use cases:
Vertex AI LLM models that have been tested on question and answering tasks
Vertex AI Search models that are based on Vertex AI LLM models and further trained to address question and answering tasks
Vertex AI Search models share the same discontinuation date as their base Vertex AI LLM models. The base LLM model is available for six months after the release date of the next version of the model, per the Vertex AI model lifecycle policy. Leave enough time to migrate to new models before the discontinuation dates.
The following table lists model version specifications. When you set a model specification, the API uses the specified model to generate answers.
Industry vertical
Custom
Healthcare
Model version
Description
Context window
Discontinuation date
Description
Context window
Discontinuation date
stable
The default model choice if the model version is not set.
The stable model specification points to gemini-2.5-flash/answer_gen/v1.
The model designated as stable changes periodically as new models and versions become available.
128K
N/A
The default model choice if the model version is not set.
The stable model specification points to gemini-2.5-flash/answer_gen/v1.
The model designated as stable changes periodically as new models and versions become available.
128K
N/A
gemini-2.5-flash/answer_gen/v1
A Vertex AI Search model based on the gemini-2.5-flash model with additional tuning to address question and answering tasks.
The model is frozen after release.
128K
June 17, 2026
A Vertex AI Search model based on the gemini-2.5-flash model with additional tuning to address question and answering tasks.
The model is frozen after release.
128K
June 17, 2026
gemini-2.0-flash-001/answer_gen/v1
A Vertex AI Search model based on the gemini-2.0-flash-001 model with additional tuning to address question and answering tasks.
The model is frozen after release.
128K
Feb 5, 2026
A Vertex AI Search model based on the gemini-2.0-flash-001 model with additional tuning to address question and answering tasks.
The model is frozen after release.
128K
Feb 5, 2026
preview
The preview model specification points to the gemini-2.5-flash model. The preview model is subject to change without notification. If you use preview as the model, you might see changes in the responses when the model changes. If you want consistency in the responses, select a specific model.
128K
N/A
The preview model specification points to the gemini-2.5-flash model. The preview model is subject to change without notification. If you use preview as the model, you might see changes in the responses when the model changes. If you want consistency in the responses, select a specific model.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-12-09 UTC."],[],[]]
