diff --git a/litellm/litellm_core_utils/litellm_logging.py b/litellm/litellm_core_utils/litellm_logging.py
index 9d1360bf057..4ad2d1002bc 100644
--- a/litellm/litellm_core_utils/litellm_logging.py
+++ b/litellm/litellm_core_utils/litellm_logging.py
@@ -1297,6 +1297,7 @@ class Logging(LiteLLMLoggingBaseClass):
         output_cost: float,
         total_cost: float,
         cost_for_built_in_tools_cost_usd_dollar: float,
+        additional_costs: Optional[dict] = None,
         original_cost: Optional[float] = None,
         discount_percent: Optional[float] = None,
         discount_amount: Optional[float] = None,
@@ -1312,6 +1313,7 @@ class Logging(LiteLLMLoggingBaseClass):
             output_cost: Cost of output/completion tokens
             cost_for_built_in_tools_cost_usd_dollar: Cost of built-in tools
             total_cost: Total cost of request
+            additional_costs: Free-form additional costs dict (e.g., {"azure_model_router_flat_cost": 0.00014})
             original_cost: Cost before discount
             discount_percent: Discount percentage (0.05 = 5%)
             discount_amount: Discount amount in USD
@@ -1327,6 +1329,10 @@ class Logging(LiteLLMLoggingBaseClass):
             tool_usage_cost=cost_for_built_in_tools_cost_usd_dollar,
         )
 
+        # Store additional costs if provided (free-form dict for extensibility)
+        if additional_costs and isinstance(additional_costs, dict) and len(additional_costs) > 0:
+            self.cost_breakdown["additional_costs"] = additional_costs
+
         # Store discount information if provided
         if original_cost is not None:
             self.cost_breakdown["original_cost"] = original_cost
diff --git a/litellm/types/utils.py b/litellm/types/utils.py
index f063418f92e..6c330d0f83c 100644
--- a/litellm/types/utils.py
+++ b/litellm/types/utils.py
@@ -2637,6 +2637,7 @@ class CostBreakdown(TypedDict, total=False):
     )
     total_cost: float  # Total cost (input + output + tool usage)
     tool_usage_cost: float  # Cost of usage of built-in tools
+    additional_costs: Dict[str, float]  # Free-form additional costs (e.g., {"azure_model_router_flat_cost": 0.00014})
     original_cost: float  # Cost before discount (optional)
     discount_percent: float  # Discount percentage applied (e.g., 0.05 = 5%) (optional)
     discount_amount: float  # Discount amount in USD (optional)