diff --git a/litellm/__init__.py b/litellm/__init__.py
index a8d9a80a2..73c382516 100644
--- a/litellm/__init__.py
+++ b/litellm/__init__.py
@@ -749,6 +749,7 @@ from .utils import (
     create_pretrained_tokenizer,
     create_tokenizer,
     supports_function_calling,
+    supports_response_schema,
     supports_parallel_function_calling,
     supports_vision,
     supports_system_messages,
diff --git a/litellm/llms/prompt_templates/factory.py b/litellm/llms/prompt_templates/factory.py
index b35914584..87af2a6bd 100644
--- a/litellm/llms/prompt_templates/factory.py
+++ b/litellm/llms/prompt_templates/factory.py
@@ -2033,6 +2033,50 @@ def function_call_prompt(messages: list, functions: list):
     return messages
 
 
+def response_schema_prompt(model: str, response_schema: dict) -> str:
+    """
+    Decides if a user-defined custom prompt or default needs to be used
+
+    Returns the prompt str that's passed to the model as a user message
+    """
+    custom_prompt_details: Optional[dict] = None
+    response_schema_as_message = [
+        {"role": "user", "content": "{}".format(response_schema)}
+    ]
+    if f"{model}/response_schema_prompt" in litellm.custom_prompt_dict:
+
+        custom_prompt_details = litellm.custom_prompt_dict[
+            f"{model}/response_schema_prompt"
+        ]  # allow user to define custom response schema prompt by model
+    elif "response_schema_prompt" in litellm.custom_prompt_dict:
+        custom_prompt_details = litellm.custom_prompt_dict["response_schema_prompt"]
+
+    if custom_prompt_details is not None:
+        return custom_prompt(
+            role_dict=custom_prompt_details["roles"],
+            initial_prompt_value=custom_prompt_details["initial_prompt_value"],
+            final_prompt_value=custom_prompt_details["final_prompt_value"],
+            messages=response_schema_as_message,
+        )
+    else:
+        return default_response_schema_prompt(response_schema=response_schema)
+
+
+def default_response_schema_prompt(response_schema: dict) -> str:
+    """
+    Used if provider/model doesn't support 'response_schema' param.
+
+    This is the default prompt. Allow user to override this with a custom_prompt.
+    """
+    prompt_str = """Use this JSON schema: 
+    ```json 
+    {}
+    ```""".format(
+        response_schema
+    )
+    return prompt_str
+
+
 # Custom prompt template
 def custom_prompt(
     role_dict: dict,
diff --git a/litellm/llms/vertex_ai.py b/litellm/llms/vertex_ai.py
index 4a4abaef4..c1e628d17 100644
--- a/litellm/llms/vertex_ai.py
+++ b/litellm/llms/vertex_ai.py
@@ -12,6 +12,7 @@ import requests  # type: ignore
 from pydantic import BaseModel
 
 import litellm
+from litellm._logging import verbose_logger
 from litellm.litellm_core_utils.core_helpers import map_finish_reason
 from litellm.llms.prompt_templates.factory import (
     convert_to_anthropic_image_obj,
@@ -328,80 +329,86 @@ def _gemini_convert_messages_with_history(messages: list) -> List[ContentType]:
     contents: List[ContentType] = []
 
     msg_i = 0
-    while msg_i < len(messages):
-        user_content: List[PartType] = []
-        init_msg_i = msg_i
-        ## MERGE CONSECUTIVE USER CONTENT ##
-        while msg_i < len(messages) and messages[msg_i]["role"] in user_message_types:
-            if isinstance(messages[msg_i]["content"], list):
-                _parts: List[PartType] = []
-                for element in messages[msg_i]["content"]:
-                    if isinstance(element, dict):
-                        if element["type"] == "text" and len(element["text"]) > 0:
-                            _part = PartType(text=element["text"])
-                            _parts.append(_part)
-                        elif element["type"] == "image_url":
-                            image_url = element["image_url"]["url"]
-                            _part = _process_gemini_image(image_url=image_url)
-                            _parts.append(_part)  # type: ignore
-                user_content.extend(_parts)
-            elif (
-                isinstance(messages[msg_i]["content"], str)
-                and len(messages[msg_i]["content"]) > 0
+    try:
+        while msg_i < len(messages):
+            user_content: List[PartType] = []
+            init_msg_i = msg_i
+            ## MERGE CONSECUTIVE USER CONTENT ##
+            while (
+                msg_i < len(messages) and messages[msg_i]["role"] in user_message_types
             ):
-                _part = PartType(text=messages[msg_i]["content"])
-                user_content.append(_part)
+                if isinstance(messages[msg_i]["content"], list):
+                    _parts: List[PartType] = []
+                    for element in messages[msg_i]["content"]:
+                        if isinstance(element, dict):
+                            if element["type"] == "text" and len(element["text"]) > 0:
+                                _part = PartType(text=element["text"])
+                                _parts.append(_part)
+                            elif element["type"] == "image_url":
+                                image_url = element["image_url"]["url"]
+                                _part = _process_gemini_image(image_url=image_url)
+                                _parts.append(_part)  # type: ignore
+                    user_content.extend(_parts)
+                elif (
+                    isinstance(messages[msg_i]["content"], str)
+                    and len(messages[msg_i]["content"]) > 0
+                ):
+                    _part = PartType(text=messages[msg_i]["content"])
+                    user_content.append(_part)
 
-            msg_i += 1
+                msg_i += 1
 
-        if user_content:
-            contents.append(ContentType(role="user", parts=user_content))
-        assistant_content = []
-        ## MERGE CONSECUTIVE ASSISTANT CONTENT ##
-        while msg_i < len(messages) and messages[msg_i]["role"] == "assistant":
-            if isinstance(messages[msg_i]["content"], list):
-                _parts = []
-                for element in messages[msg_i]["content"]:
-                    if isinstance(element, dict):
-                        if element["type"] == "text":
-                            _part = PartType(text=element["text"])
-                            _parts.append(_part)
-                        elif element["type"] == "image_url":
-                            image_url = element["image_url"]["url"]
-                            _part = _process_gemini_image(image_url=image_url)
-                            _parts.append(_part)  # type: ignore
-                assistant_content.extend(_parts)
-            elif messages[msg_i].get(
-                "tool_calls", []
-            ):  # support assistant tool invoke conversion
-                assistant_content.extend(
-                    convert_to_gemini_tool_call_invoke(messages[msg_i]["tool_calls"])
+            if user_content:
+                contents.append(ContentType(role="user", parts=user_content))
+            assistant_content = []
+            ## MERGE CONSECUTIVE ASSISTANT CONTENT ##
+            while msg_i < len(messages) and messages[msg_i]["role"] == "assistant":
+                if isinstance(messages[msg_i]["content"], list):
+                    _parts = []
+                    for element in messages[msg_i]["content"]:
+                        if isinstance(element, dict):
+                            if element["type"] == "text":
+                                _part = PartType(text=element["text"])
+                                _parts.append(_part)
+                            elif element["type"] == "image_url":
+                                image_url = element["image_url"]["url"]
+                                _part = _process_gemini_image(image_url=image_url)
+                                _parts.append(_part)  # type: ignore
+                    assistant_content.extend(_parts)
+                elif messages[msg_i].get(
+                    "tool_calls", []
+                ):  # support assistant tool invoke conversion
+                    assistant_content.extend(
+                        convert_to_gemini_tool_call_invoke(
+                            messages[msg_i]["tool_calls"]
+                        )
+                    )
+                else:
+                    assistant_text = (
+                        messages[msg_i].get("content") or ""
+                    )  # either string or none
+                    if assistant_text:
+                        assistant_content.append(PartType(text=assistant_text))
+
+                msg_i += 1
+
+            if assistant_content:
+                contents.append(ContentType(role="model", parts=assistant_content))
+
+            ## APPEND TOOL CALL MESSAGES ##
+            if msg_i < len(messages) and messages[msg_i]["role"] == "tool":
+                _part = convert_to_gemini_tool_call_result(messages[msg_i])
+                contents.append(ContentType(parts=[_part]))  # type: ignore
+                msg_i += 1
+            if msg_i == init_msg_i:  # prevent infinite loops
+                raise Exception(
+                    "Invalid Message passed in - {}. File an issue https://github.com/BerriAI/litellm/issues".format(
+                        messages[msg_i]
+                    )
                 )
-            else:
-                assistant_text = (
-                    messages[msg_i].get("content") or ""
-                )  # either string or none
-                if assistant_text:
-                    assistant_content.append(PartType(text=assistant_text))
-
-            msg_i += 1
-
-        if assistant_content:
-            contents.append(ContentType(role="model", parts=assistant_content))
-
-        ## APPEND TOOL CALL MESSAGES ##
-        if msg_i < len(messages) and messages[msg_i]["role"] == "tool":
-            _part = convert_to_gemini_tool_call_result(messages[msg_i])
-            contents.append(ContentType(parts=[_part]))  # type: ignore
-            msg_i += 1
-        if msg_i == init_msg_i:  # prevent infinite loops
-            raise Exception(
-                "Invalid Message passed in - {}. File an issue https://github.com/BerriAI/litellm/issues".format(
-                    messages[msg_i]
-                )
-            )
-
-    return contents
+        return contents
+    except Exception as e:
+        raise e
 
 
 def _get_client_cache_key(model: str, vertex_project: str, vertex_location: str):
diff --git a/litellm/llms/vertex_httpx.py b/litellm/llms/vertex_httpx.py
index 940016ecb..91a2b0276 100644
--- a/litellm/llms/vertex_httpx.py
+++ b/litellm/llms/vertex_httpx.py
@@ -21,7 +21,10 @@ import litellm.litellm_core_utils.litellm_logging
 from litellm import verbose_logger
 from litellm.litellm_core_utils.core_helpers import map_finish_reason
 from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler, HTTPHandler
-from litellm.llms.prompt_templates.factory import convert_url_to_base64
+from litellm.llms.prompt_templates.factory import (
+    convert_url_to_base64,
+    response_schema_prompt,
+)
 from litellm.llms.vertex_ai import _gemini_convert_messages_with_history
 from litellm.types.llms.openai import (
     ChatCompletionResponseMessage,
@@ -1011,35 +1014,53 @@ class VertexLLM(BaseLLM):
             if len(system_prompt_indices) > 0:
                 for idx in reversed(system_prompt_indices):
                     messages.pop(idx)
-        content = _gemini_convert_messages_with_history(messages=messages)
-        tools: Optional[Tools] = optional_params.pop("tools", None)
-        tool_choice: Optional[ToolConfig] = optional_params.pop("tool_choice", None)
-        safety_settings: Optional[List[SafetSettingsConfig]] = optional_params.pop(
-            "safety_settings", None
-        )  # type: ignore
-        generation_config: Optional[GenerationConfig] = GenerationConfig(
-            **optional_params
-        )
-        data = RequestBody(contents=content)
-        if len(system_content_blocks) > 0:
-            system_instructions = SystemInstructions(parts=system_content_blocks)
-            data["system_instruction"] = system_instructions
-        if tools is not None:
-            data["tools"] = tools
-        if tool_choice is not None:
-            data["toolConfig"] = tool_choice
-        if safety_settings is not None:
-            data["safetySettings"] = safety_settings
-        if generation_config is not None:
-            data["generationConfig"] = generation_config
 
-        headers = {
-            "Content-Type": "application/json",
-        }
-        if auth_header is not None:
-            headers["Authorization"] = f"Bearer {auth_header}"
-        if extra_headers is not None:
-            headers.update(extra_headers)
+        # Checks for 'response_schema' support - if passed in
+        if "response_schema" in optional_params:
+            supports_response_schema = litellm.supports_response_schema(
+                model=model, custom_llm_provider="vertex_ai"
+            )
+            if supports_response_schema is False:
+                user_response_schema_message = response_schema_prompt(
+                    model=model, response_schema=optional_params.get("response_schema")  # type: ignore
+                )
+                messages.append(
+                    {"role": "user", "content": user_response_schema_message}
+                )
+                optional_params.pop("response_schema")
+
+        try:
+            content = _gemini_convert_messages_with_history(messages=messages)
+            tools: Optional[Tools] = optional_params.pop("tools", None)
+            tool_choice: Optional[ToolConfig] = optional_params.pop("tool_choice", None)
+            safety_settings: Optional[List[SafetSettingsConfig]] = optional_params.pop(
+                "safety_settings", None
+            )  # type: ignore
+            generation_config: Optional[GenerationConfig] = GenerationConfig(
+                **optional_params
+            )
+            data = RequestBody(contents=content)
+            if len(system_content_blocks) > 0:
+                system_instructions = SystemInstructions(parts=system_content_blocks)
+                data["system_instruction"] = system_instructions
+            if tools is not None:
+                data["tools"] = tools
+            if tool_choice is not None:
+                data["toolConfig"] = tool_choice
+            if safety_settings is not None:
+                data["safetySettings"] = safety_settings
+            if generation_config is not None:
+                data["generationConfig"] = generation_config
+
+            headers = {
+                "Content-Type": "application/json",
+            }
+            if auth_header is not None:
+                headers["Authorization"] = f"Bearer {auth_header}"
+            if extra_headers is not None:
+                headers.update(extra_headers)
+        except Exception as e:
+            raise e
 
         ## LOGGING
         logging_obj.pre_call(
diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index 49f2f0c28..7f08b9eb1 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -1538,6 +1538,7 @@
         "supports_system_messages": true,
         "supports_function_calling": true,
         "supports_tool_choice": true, 
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-pro-preview-0215": { 
@@ -1563,6 +1564,7 @@
         "supports_system_messages": true,
         "supports_function_calling": true,
         "supports_tool_choice": true, 
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-pro-preview-0409": {
@@ -1586,7 +1588,8 @@
         "litellm_provider": "vertex_ai-language-models",
         "mode": "chat",
         "supports_function_calling": true,
-        "supports_tool_choice": true, 
+        "supports_tool_choice": true,
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-flash": {
diff --git a/litellm/tests/test_amazing_vertex_completion.py b/litellm/tests/test_amazing_vertex_completion.py
index e6f2634f4..4cb79affa 100644
--- a/litellm/tests/test_amazing_vertex_completion.py
+++ b/litellm/tests/test_amazing_vertex_completion.py
@@ -880,10 +880,19 @@ Using this JSON schema:
         mock_call.assert_called_once()
 
 
-@pytest.mark.parametrize("provider", ["vertex_ai_beta"])  # "vertex_ai",
+@pytest.mark.parametrize(
+    "model, supports_response_schema",
+    [
+        ("vertex_ai_beta/gemini-1.5-pro-001", True),
+        ("vertex_ai_beta/gemini-1.5-flash", False),
+    ],
+)  # "vertex_ai",
 @pytest.mark.asyncio
-async def test_gemini_pro_json_schema_httpx(provider):
+async def test_gemini_pro_json_schema_httpx(model, supports_response_schema):
     load_vertex_ai_credentials()
+    os.environ["LITELLM_LOCAL_MODEL_COST_MAP"] = "True"
+    litellm.model_cost = litellm.get_model_cost_map(url="")
+
     litellm.set_verbose = True
     messages = [{"role": "user", "content": "List 5 cookie recipes"}]
     from litellm.llms.custom_httpx.http_handler import HTTPHandler
@@ -905,8 +914,8 @@ async def test_gemini_pro_json_schema_httpx(provider):
 
     with patch.object(client, "post", new=MagicMock()) as mock_call:
         try:
-            response = completion(
-                model="vertex_ai_beta/gemini-1.5-pro-001",
+            _ = completion(
+                model=model,
                 messages=messages,
                 response_format={
                     "type": "json_object",
@@ -914,15 +923,27 @@ async def test_gemini_pro_json_schema_httpx(provider):
                 },
                 client=client,
             )
-        except Exception as e:
+        except Exception:
             pass
 
         mock_call.assert_called_once()
         print(mock_call.call_args.kwargs)
         print(mock_call.call_args.kwargs["json"]["generationConfig"])
-        assert (
-            "response_schema" in mock_call.call_args.kwargs["json"]["generationConfig"]
-        )
+
+        if supports_response_schema:
+            assert (
+                "response_schema"
+                in mock_call.call_args.kwargs["json"]["generationConfig"]
+            )
+        else:
+            assert (
+                "response_schema"
+                not in mock_call.call_args.kwargs["json"]["generationConfig"]
+            )
+            assert (
+                "Use this JSON schema:"
+                in mock_call.call_args.kwargs["json"]["contents"][0]["parts"][1]["text"]
+            )
 
 
 @pytest.mark.parametrize("provider", ["vertex_ai_beta"])  # "vertex_ai",
diff --git a/litellm/utils.py b/litellm/utils.py
index 227274d3a..91cf75424 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -1879,8 +1879,7 @@ def supports_response_schema(model: str, custom_llm_provider: Optional[str]) ->
     Returns:
     bool: True if the model supports response_schema, False otherwise.
 
-    Raises:
-    Exception: If the given model is not found in model_prices_and_context_window.json.
+    Does not raise error. Defaults to 'False'. Outputs logging.error.
     """
     try:
         ## GET LLM PROVIDER ##
@@ -1900,9 +1899,10 @@ def supports_response_schema(model: str, custom_llm_provider: Optional[str]) ->
             return True
         return False
     except Exception:
-        raise Exception(
+        verbose_logger.error(
             f"Model not in model_prices_and_context_window.json. You passed model={model}, custom_llm_provider={custom_llm_provider}."
         )
+        return False
 
 
 def supports_function_calling(model: str) -> bool:
diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index 49f2f0c28..7f08b9eb1 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -1538,6 +1538,7 @@
         "supports_system_messages": true,
         "supports_function_calling": true,
         "supports_tool_choice": true, 
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-pro-preview-0215": { 
@@ -1563,6 +1564,7 @@
         "supports_system_messages": true,
         "supports_function_calling": true,
         "supports_tool_choice": true, 
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-pro-preview-0409": {
@@ -1586,7 +1588,8 @@
         "litellm_provider": "vertex_ai-language-models",
         "mode": "chat",
         "supports_function_calling": true,
-        "supports_tool_choice": true, 
+        "supports_tool_choice": true,
+        "supports_response_schema": true, 
         "source": "https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models#foundation_models"
     },
     "gemini-1.5-flash": {