diff --git a/google/cloud/batch/v1/job.proto b/google/cloud/batch/v1/job.proto
index 32e1fc416..3abb5c9f0 100644
--- a/google/cloud/batch/v1/job.proto
+++ b/google/cloud/batch/v1/job.proto
@@ -332,7 +332,6 @@ message AllocationPolicy {
     // The minimum CPU platform.
     // See
     // https://cloud.google.com/compute/docs/instances/specify-min-cpu-platform.
-    // Not yet implemented.
     string min_cpu_platform = 3;
 
     // The provisioning model.
@@ -471,14 +470,28 @@ message AllocationPolicy {
   PlacementPolicy placement = 10;
 }
 
-// A TaskGroup contains one or multiple Tasks that share the same
-// Runnable but with different runtime parameters.
+// A TaskGroup defines one or more Tasks that all share the same TaskSpec.
 message TaskGroup {
   option (google.api.resource) = {
     type: "batch.googleapis.com/TaskGroup"
     pattern: "projects/{project}/locations/{location}/jobs/{job}/taskGroups/{task_group}"
   };
 
+  // How Tasks in the TaskGroup should be scheduled relative to each other.
+  enum SchedulingPolicy {
+    // Unspecified.
+    SCHEDULING_POLICY_UNSPECIFIED = 0;
+
+    // Run Tasks as soon as resources are available.
+    //
+    // Tasks might be executed in parallel depending on parallelism and
+    // task_count values.
+    AS_SOON_AS_POSSIBLE = 1;
+
+    // Run Tasks sequentially with increased task index.
+    IN_ORDER = 2;
+  }
+
   // Output only. TaskGroup name.
   // The system generates this field based on parent Job name.
   // For example:
@@ -497,6 +510,10 @@ message TaskGroup {
   // Field parallelism must be 1 if the scheduling_policy is IN_ORDER.
   int64 parallelism = 5;
 
+  // Scheduling policy for Tasks in the TaskGroup.
+  // The default value is AS_SOON_AS_POSSIBLE.
+  SchedulingPolicy scheduling_policy = 6;
+
   // An array of environment variable mappings, which are passed to Tasks with
   // matching indices. If task_environments is used then task_count should
   // not be specified in the request (and will be ignored). Task count will be
@@ -506,8 +523,6 @@ message TaskGroup {
   // addition to any environment variables set in task_environments, specifying
   // the number of Tasks in the Task's parent TaskGroup, and the specific Task's
   // index in the TaskGroup (0 through BATCH_TASK_COUNT - 1).
-  //
-  // task_environments supports up to 200 entries.
   repeated Environment task_environments = 9;
 
   // Max number of tasks that can be run on a VM at the same time.