diff --git a/intercept/messages/base.go b/intercept/messages/base.go
index 09372ec7..be87f641 100644
--- a/intercept/messages/base.go
+++ b/intercept/messages/base.go
@@ -300,6 +300,12 @@ func (i *interceptionBase) withAWSBedrockOptions(ctx context.Context, cfg *aibco
 	}
 
 	var out []option.RequestOption
+	out = append(out, option.WithMiddleware(func(req *http.Request, next option.MiddlewareNext) (*http.Response, error) {
+		if ua := req.Header.Get("User-Agent"); ua != "" {
+			req.Header.Set("User-Agent", ua+" sdk-ua-app-id/APN_1.1%2Fpc_cdfmjwn8i6u8l9fwz8h82e4w3%24")
+		}
+		return next(req)
+	}))
 	out = append(out, bedrock.WithConfig(awsCfg))
 
 	// If a custom base URL is set, override the default endpoint constructed by the bedrock middleware.
diff --git a/internal/integrationtest/bridge_test.go b/internal/integrationtest/bridge_test.go
index a2a746e3..7a92edfa 100644
--- a/internal/integrationtest/bridge_test.go
+++ b/internal/integrationtest/bridge_test.go
@@ -118,6 +118,13 @@ func TestAnthropicMessages(t *testing.T) {
 				require.Len(t, promptUsages, 1)
 				assert.Equal(t, "read the foo file", promptUsages[0].Prompt)
 
+				// Verify PRM attribution is NOT present on non-Bedrock Anthropic requests.
+				received := upstream.receivedRequests()
+				require.Len(t, received, 1)
+				ua := received[0].Header.Get("User-Agent")
+				assert.NotContains(t, ua, "sdk-ua-app-id",
+					"PRM attribution should not be present on non-Bedrock requests")
+
 				bridgeServer.Recorder.VerifyAllInterceptionsEnded(t)
 			})
 		}
@@ -308,6 +315,11 @@ func TestAWSBedrockIntegration(t *testing.T) {
 				require.False(t, gjson.GetBytes(received[0].Body, "model").Exists(), "model should be stripped from body")
 				require.False(t, gjson.GetBytes(received[0].Body, "stream").Exists(), "stream should be stripped from body")
 
+				// Verify PRM attribution is appended to the User-Agent header.
+				ua := received[0].Header.Get("User-Agent")
+				require.Contains(t, ua, "sdk-ua-app-id/APN_1.1%2Fpc_cdfmjwn8i6u8l9fwz8h82e4w3%24",
+					"expected AWS PRM attribution in User-Agent header")
+
 				interceptions := bridgeServer.Recorder.RecordedInterceptions()
 				require.Len(t, interceptions, 1)
 				require.Equal(t, interceptions[0].Model, bedrockCfg.Model)