diff --git a/vehicle-data-platform/apps/api/internal/platform/handler_test.go b/vehicle-data-platform/apps/api/internal/platform/handler_test.go
index 45880d41..8cde2362 100644
--- a/vehicle-data-platform/apps/api/internal/platform/handler_test.go
+++ b/vehicle-data-platform/apps/api/internal/platform/handler_test.go
@@ -49,6 +49,22 @@ func TestHandlerVehicles(t *testing.T) {
 	}
 }
 
+func TestHandlerVehiclesFiltersServiceStatus(t *testing.T) {
+	handler := NewHandler(NewService(NewMockStore()))
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/vehicles?limit=10&serviceStatus=degraded", nil)
+	handler.ServeHTTP(rec, req)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d body=%s", rec.Code, rec.Body.String())
+	}
+	if !strings.Contains(rec.Body.String(), "LB9A32A24R0LS1426") {
+		t.Fatalf("degraded vehicles should include partially online vehicle: %s", rec.Body.String())
+	}
+	if strings.Contains(rec.Body.String(), "LMRKH9AC2R1004087") {
+		t.Fatalf("degraded vehicles should exclude healthy vehicle: %s", rec.Body.String())
+	}
+}
+
 func TestHandlerVehicleCoverage(t *testing.T) {
 	handler := NewHandler(NewService(NewMockStore()))
 	rec := httptest.NewRecorder()
diff --git a/vehicle-data-platform/apps/api/internal/platform/mock_store.go b/vehicle-data-platform/apps/api/internal/platform/mock_store.go
index dd387a5a..f41079de 100644
--- a/vehicle-data-platform/apps/api/internal/platform/mock_store.go
+++ b/vehicle-data-platform/apps/api/internal/platform/mock_store.go
@@ -61,10 +61,14 @@ func (m *MockStore) DashboardSummary(context.Context) (DashboardSummary, error)
 
 func (m *MockStore) Vehicles(_ context.Context, query url.Values) (Page[VehicleRow], error) {
 	items := filterVehicles(m.vehicles, query)
-	for index := range items {
-		items[index].ServiceStatus = m.vehicleRowServiceStatus(items[index])
+	enriched := make([]VehicleRow, 0, len(items))
+	for _, item := range items {
+		item.ServiceStatus = m.vehicleRowServiceStatus(item)
+		if keepServiceStatus(item.ServiceStatus, query.Get("serviceStatus")) {
+			enriched = append(enriched, item)
+		}
 	}
-	return page(items, query), nil
+	return page(enriched, query), nil
 }
 
 func (m *MockStore) vehicleRowServiceStatus(row VehicleRow) *VehicleServiceStatus {
diff --git a/vehicle-data-platform/apps/api/internal/platform/mysql_queries.go b/vehicle-data-platform/apps/api/internal/platform/mysql_queries.go
index d1d2ec16..a1170722 100644
--- a/vehicle-data-platform/apps/api/internal/platform/mysql_queries.go
+++ b/vehicle-data-platform/apps/api/internal/platform/mysql_queries.go
@@ -27,6 +27,16 @@ func buildVehicleListSQL(query url.Values) SQLQuery {
 		where = append(where, "s.protocol = ?")
 		args = append(args, protocol)
 	}
+	switch strings.TrimSpace(query.Get("serviceStatus")) {
+	case "identity_required":
+		where = append(where, "(b.vin IS NULL OR b.vin = '')")
+	case "offline":
+		where = append(where, "b.vin IS NOT NULL", "b.vin <> ''", "COALESCE(vs.source_count, 0) > 0", "COALESCE(vs.online_source_count, 0) = 0")
+	case "degraded":
+		where = append(where, "b.vin IS NOT NULL", "b.vin <> ''", "vs.source_count > 0", "vs.online_source_count > 0", "vs.online_source_count < vs.source_count")
+	case "healthy":
+		where = append(where, "b.vin IS NOT NULL", "b.vin <> ''", "vs.source_count > 0", "vs.online_source_count = vs.source_count")
+	}
 	countArgs := append([]any(nil), args...)
 	args = append(args, limit, offset)
 	fromSQL := `FROM vehicle_realtime_snapshot s ` +
diff --git a/vehicle-data-platform/apps/api/internal/platform/query_builders_test.go b/vehicle-data-platform/apps/api/internal/platform/query_builders_test.go
index 9d579842..9bc3944d 100644
--- a/vehicle-data-platform/apps/api/internal/platform/query_builders_test.go
+++ b/vehicle-data-platform/apps/api/internal/platform/query_builders_test.go
@@ -26,6 +26,23 @@ func TestBuildVehicleListSQL(t *testing.T) {
 	}
 }
 
+func TestBuildVehicleListSQLFiltersServiceStatus(t *testing.T) {
+	query := url.Values{"serviceStatus": {"degraded"}, "limit": {"8"}}
+	built := buildVehicleListSQL(query)
+	for _, want := range []string{
+		"vs.source_count > 0",
+		"vs.online_source_count > 0",
+		"vs.online_source_count < vs.source_count",
+	} {
+		if !strings.Contains(built.Text, want) {
+			t.Fatalf("SQL missing vehicle list service status predicate %q: %s", want, built.Text)
+		}
+	}
+	if !strings.Contains(built.CountText, "vs.source_count > 0") || !strings.Contains(built.CountText, "vs.online_source_count < vs.source_count") {
+		t.Fatalf("count SQL should include vehicle list service status predicate: %s", built.CountText)
+	}
+}
+
 func TestBuildVehicleCoverageSQL(t *testing.T) {
 	query := url.Values{"keyword": {"粤A"}, "protocol": {"GB32960"}, "coverage": {"multi"}, "online": {"online"}, "bindingStatus": {"bound"}, "limit": {"8"}, "offset": {"16"}}
 	built := buildVehicleCoverageSQL(query)