diff --git a/bigquery/inserter.go b/bigquery/inserter.go
index 2a12bb3..789cd00 100644
--- a/bigquery/inserter.go
+++ b/bigquery/inserter.go
@@ -24,6 +24,11 @@
 	bq "google.golang.org/api/bigquery/v2"
 )
 
+// NoDedupeID indicates a streaming insert row wants to opt out of best-effort
+// deduplication.
+// It is EXPERIMENTAL and subject to change or removal without notice.
+const NoDedupeID = "NoDedupeID"
+
 // An Inserter does streaming inserts into a BigQuery table.
 // It is safe for concurrent use.
 type Inserter struct {
@@ -200,7 +205,9 @@
 		if err != nil {
 			return nil, err
 		}
-		if insertID == "" {
+		if insertID == NoDedupeID {
+			insertID = ""
+		} else if insertID == "" {
 			insertID = randomIDFn()
 		}
 		m := make(map[string]bq.JsonValue)
diff --git a/bigquery/inserter_test.go b/bigquery/inserter_test.go
index 0fafeac..8216ecb 100644
--- a/bigquery/inserter_test.go
+++ b/bigquery/inserter_test.go
@@ -56,11 +56,13 @@
 			savers: []ValueSaver{
 				testSaver{row: map[string]Value{"one": 1}},
 				testSaver{row: map[string]Value{"two": 2}},
+				testSaver{insertID: NoDedupeID, row: map[string]Value{"three": 3}},
 			},
 			req: &bq.TableDataInsertAllRequest{
 				Rows: []*bq.TableDataInsertAllRequestRows{
 					{InsertId: "1", Json: map[string]bq.JsonValue{"one": 1}},
 					{InsertId: "2", Json: map[string]bq.JsonValue{"two": 2}},
+					{InsertId: "", Json: map[string]bq.JsonValue{"three": 3}},
 				},
 			},
 		},