Answer generation model versions and lifecycle

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.

Model version Generic Healthcare
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-2.0-flash-001/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-1.5-flash-001/answer_gen/v1.

The model designated as stable changes periodically as new models and versions become available.

128K N/A
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
gemini-1.5-flash-002/answer_gen/v1

A Vertex AI Search model based on the gemini-1.5-flash-002 model with additional tuning to address question and answering tasks.

The model is frozen after release.

128K Sept 24, 2025 Not Available
gemini-1.5-flash-001/answer_gen/v2

A Vertex AI Search model based on the gemini-1.5-flash-001 model with additional tuning (version 2) on blended structured and unstructured data to address question and answering tasks.

The model is frozen after release.

128K May 24, 2025

A Vertex AI Search model based on the gemini-1.5-flash-001 model with additional tuning (version 2) on blended structured and unstructured data to address question and answering tasks.

The model is frozen after release.

128K May 24, 2025
gemini-1.5-flash-001/answer_gen/v1

A Vertex AI Search model based on the gemini-1.5-flash-001 model with additional tuning to address question and answering tasks.

The model is frozen after release.

128K May 24, 2025

A Vertex AI Search model based on the gemini-1.5-flash-001 model with additional tuning to address question and answering tasks.

The model is frozen after release.

128K May 24, 2025
gemini-1.0-pro-002/answer_gen/v1

A Vertex AI Search based on the gemini-1.0-pro-002 model with additional training to address question and answering tasks.

The model is frozen after release.

32K April 9, 2025

A Vertex AI Search model based on the gemini-1.0-pro-002 model with additional training to address question and answering tasks.

The model is frozen after release.

32K April 9, 2025
gemini-1.0-pro-001/answer_gen/v1

Points to the gemini-1.0-pro-001 model.

The model is frozen after release.

32K April 9, 2025 Not Available
preview

The preview model specification points to the latest gemini-1.5-pro-002 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 latest gemini-1.5-pro-002 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

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