diff --git a/nomyo/SecureCompletionClient.py b/nomyo/SecureCompletionClient.py
index 8f2be54..27d3863 100644
--- a/nomyo/SecureCompletionClient.py
+++ b/nomyo/SecureCompletionClient.py
@@ -616,7 +616,7 @@ class SecureCompletionClient:
 
         return response
 
-    async def send_secure_request(self, payload: Dict[str, Any], payload_id: str, api_key: Optional[str] = None) -> Dict[str, Any]:
+    async def send_secure_request(self, payload: Dict[str, Any], payload_id: str, api_key: Optional[str] = None, security_tier: Optional[str] = None) -> Dict[str, Any]:
         """
         Send a secure chat completion request to the router.
 
@@ -624,6 +624,12 @@ class SecureCompletionClient:
             payload: Chat completion request payload
             payload_id: Unique identifier for this request
             api_key: Optional API key for bearer authentication
+            security_tier: Optional security tier for routing ("standard", "high", or "maximum").
+                          Controls hardware preference:
+                          - "standard": general secure inference
+                          - "high": sensitive business data
+                          - "maximum": maximum isolation (PHI, classified data)
+                          If not specified, server uses default based on model name mapping.
 
         Returns:
             Decrypted response from the LLM
@@ -634,9 +640,19 @@ class SecureCompletionClient:
             APIError: For other HTTP errors
             APIConnectionError: If connection fails
             SecurityError: If encryption/decryption fails
+            ValueError: If security_tier is invalid
         """
         logger.info("Sending secure chat completion request...")
 
+        # Validate security tier if provided
+        if security_tier is not None:
+            valid_tiers = ["standard", "high", "maximum"]
+            if security_tier not in valid_tiers:
+                raise ValueError(
+                    f"Invalid security_tier: '{security_tier}'. "
+                    f"Must be one of: {', '.join(valid_tiers)}"
+                )
+
         # Step 1: Encrypt the payload
         encrypted_payload = await self.encrypt_payload(payload)
 
@@ -651,6 +667,10 @@ class SecureCompletionClient:
         if api_key:
             headers["Authorization"] = f"Bearer {api_key}"
 
+        # Add Security-Tier header if security_tier is provided
+        if security_tier:
+            headers["X-Security-Tier"] = security_tier
+
         # Step 3: Send request to router
         url = f"{self.router_url}/v1/chat/secure_completion"
         logger.debug("Target URL: %s", url)
diff --git a/nomyo/nomyo.py b/nomyo/nomyo.py
index bfd02d0..59a61d3 100644
--- a/nomyo/nomyo.py
+++ b/nomyo/nomyo.py
@@ -120,6 +120,12 @@ class SecureChatCompletion:
                 - logit_bias: Dict[str, float]
                 - user: str
                 - base_url: str (alternative to initializing with router_url)
+                - security_tier: str ("standard", "high", or "maximum")
+                    Controls hardware routing and security level:
+                    * "standard": general secure inference
+                    * "high": sensitive business data
+                    * "maximum": maximum isolation (PHI, classified data)
+                    If not specified, server uses default based on model name mapping.
 
         Returns:
             A dictionary containing the chat completion response with the following structure:
@@ -153,6 +159,9 @@ class SecureChatCompletion:
         """
         # Extract base_url if provided (OpenAI compatibility)
         base_url = kwargs.pop("base_url", None)
+        
+        # Extract security_tier if provided
+        security_tier = kwargs.pop("security_tier", None)
 
         # Use the instance's client unless base_url is explicitly overridden
         if base_url is not None:
@@ -179,8 +188,8 @@ class SecureChatCompletion:
         # Use instance's api_key if not overridden in kwargs
         request_api_key = kwargs.pop("api_key", instance.api_key)
 
-        # Send secure request
-        response = await instance.client.send_secure_request(payload, payload_id, request_api_key)
+        # Send secure request with security tier
+        response = await instance.client.send_secure_request(payload, payload_id, request_api_key, security_tier)
 
         return response