diff --git a/extensions/copilot/src/extension/prompt/node/chatMLFetcher.ts b/extensions/copilot/src/extension/prompt/node/chatMLFetcher.ts
index 97a41d0380bdaa..4b2a2ebfd57e6d 100644
--- a/extensions/copilot/src/extension/prompt/node/chatMLFetcher.ts
+++ b/extensions/copilot/src/extension/prompt/node/chatMLFetcher.ts
@@ -536,6 +536,7 @@ export class ChatMLFetcherImpl extends AbstractChatMLFetcher {
 							source: telemetryProperties.messageSource ?? 'unknown',
 							requestId: ourRequestId,
 							model: chatEndpoint.model,
+							modelProvider: chatEndpoint.modelProvider,
 							apiType: chatEndpoint.apiType,
 							transport,
 							interactionType,
@@ -692,6 +693,7 @@ export class ChatMLFetcherImpl extends AbstractChatMLFetcher {
 						source: telemetryProperties.messageSource ?? 'unknown',
 						requestId: ourRequestId,
 						model: chatEndpoint.model,
+						modelProvider: chatEndpoint.modelProvider,
 						apiType: chatEndpoint.apiType,
 						transport,
 						interactionType,
diff --git a/extensions/copilot/src/extension/prompt/node/chatMLFetcherTelemetry.ts b/extensions/copilot/src/extension/prompt/node/chatMLFetcherTelemetry.ts
index cabb725591e6e8..ae74da5bc322c0 100644
--- a/extensions/copilot/src/extension/prompt/node/chatMLFetcherTelemetry.ts
+++ b/extensions/copilot/src/extension/prompt/node/chatMLFetcherTelemetry.ts
@@ -38,6 +38,7 @@ export interface IChatMLFetcherCancellationProperties {
 	source: string;
 	requestId: string;
 	model: string;
+	modelProvider: string | undefined;
 	apiType: string | undefined;
 	transport: string;
 	interactionType: string;
@@ -148,6 +149,7 @@ export class ChatMLFetcherTelemetrySender {
 				"requestKind": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Resolved X-Interaction-Type for the request: 'conversation-agent', 'conversation-subagent', 'conversation-background', 'conversation-panel', 'conversation-inline', 'conversation-edits', 'conversation-other', 'conversation-notebook', or 'conversation-terminal'" },
 				"model": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Model selection for the response" },
 				"modelInvoked": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Actual model invoked for the response" },
+				"modelProvider": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Provider/vendor backing the model (e.g. for BYOK: Ollama, Azure, Anthropic, Gemini, OpenAI, OpenRouter, xAI, CustomOAI). Lets BYOK requests be attributed by provider even when the raw model id is redacted." },
 				"apiType": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "API type for the response- chat completions or responses" },
 				"conversationId": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Id for the current chat conversation." },
 				"requestId": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Id of the current turn request" },
@@ -218,6 +220,7 @@ export class ChatMLFetcherTelemetrySender {
 			conversationId: baseTelemetry?.properties.conversationId,
 			model: chatEndpointInfo?.model,
 			modelInvoked: chatCompletion.model,
+			modelProvider: chatEndpointInfo?.modelProvider,
 			apiType: chatEndpointInfo?.apiType,
 			requestId: chatCompletion.requestId.headerRequestId,
 			gitHubRequestId: chatCompletion.requestId.gitHubRequestId,
@@ -270,6 +273,7 @@ export class ChatMLFetcherTelemetrySender {
 			source,
 			requestId,
 			model,
+			modelProvider,
 			apiType,
 			transport,
 			interactionType,
@@ -305,6 +309,7 @@ export class ChatMLFetcherTelemetrySender {
 				"owner": "digitarald",
 				"comment": "Report canceled service responses for quality.",
 				"model": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Model selection for the response" },
+				"modelProvider": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Provider/vendor backing the model (e.g. for BYOK: Ollama, Azure, Anthropic, Gemini, OpenAI, OpenRouter, xAI, CustomOAI). Lets BYOK requests be attributed by provider even when the raw model id is redacted." },
 				"apiType": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "API type for the response- chat completions or responses" },
 				"source": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Source for why the request was made" },
 				"requestKind": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Resolved X-Interaction-Type for the request: 'conversation-agent', 'conversation-subagent', 'conversation-background', 'conversation-panel', 'conversation-inline', 'conversation-edits', 'conversation-other', 'conversation-notebook', or 'conversation-terminal'" },
@@ -357,6 +362,7 @@ export class ChatMLFetcherTelemetrySender {
 			source,
 			requestId,
 			model,
+			modelProvider,
 			requestKind: interactionType,
 			conversationId,
 			associatedRequestId,
@@ -416,6 +422,7 @@ export class ChatMLFetcherTelemetrySender {
 				"type": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Type of issue" },
 				"reason": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Reason of issue" },
 				"model": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Model selection for the response" },
+				"modelProvider": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Provider/vendor backing the model (e.g. for BYOK: Ollama, Azure, Anthropic, Gemini, OpenAI, OpenRouter, xAI, CustomOAI). Lets BYOK requests be attributed by provider even when the raw model id is redacted." },
 				"apiType": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "API type for the response- chat completions or responses" },
 				"source": { "classification": "SystemMetaData", "purpose": "PerformanceAndHealth", "comment": "Source for why the request was made" },
 				"requestKind": { "classification": "SystemMetaData", "purpose": "FeatureInsight", "comment": "Resolved X-Interaction-Type for the request: 'conversation-agent', 'conversation-subagent', 'conversation-background', 'conversation-panel', 'conversation-inline', 'conversation-edits', 'conversation-other', 'conversation-notebook', or 'conversation-terminal'" },
@@ -474,6 +481,7 @@ export class ChatMLFetcherTelemetrySender {
 			requestId: processed.requestId,
 			gitHubRequestId: processed.serverRequestId,
 			model: chatEndpointInfo.model,
+			modelProvider: chatEndpointInfo.modelProvider,
 			apiType: chatEndpointInfo.apiType,
 			conversationId: telemetryProperties?.conversationId,
 			reasoningEffort: requestBody.reasoning?.effort ?? requestBody.output_config?.effort,