diff --git a/hack/update_owners.py b/hack/update_owners.py
index 97d9d3f3a67..e6c3d06d04b 100755
--- a/hack/update_owners.py
+++ b/hack/update_owners.py
@@ -30,6 +30,7 @@ import zlib
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 OWNERS_PATH = os.path.abspath(
     os.path.join(BASE_DIR, '..', 'test', 'test_owners.csv'))
+OWNERS_JSON_PATH = OWNERS_PATH.replace('.csv', '.json')
 GCS_URL_BASE = 'https://storage.googleapis.com/kubernetes-test-history/'
 SKIP_MAINTAINERS = {
     'a-robinson', 'aronchick', 'bgrant0607-nocc', 'david-mcmahon',
@@ -124,12 +125,44 @@ def detect_github_username():
                      '`git config remote.origin.url` output, run with --user instead')
 
 
+def sig_prefixes(owners):
+    # TODO(rmmh): make sig prefixes the only thing in test_owners!
+    # Precise test names aren't very interesting.
+    owns = []
+
+    for test, (owner, random_assignment, sig) in owners.iteritems():
+        if 'k8s.io/' in test or not sig:
+            continue
+        owns.append([test, sig])
+
+    while True:
+        owns.sort()
+        for name, sig in owns:
+            # try removing the last word in the name, use it if all tests beginning
+            # with this shorter name share the same sig.
+            maybe_prefix = ' '.join(name.split()[:-1])
+            matches = [other_sig == sig for other_name, other_sig in owns if other_name.startswith(maybe_prefix)]
+            if matches and all(matches):
+                owns = [[n, s] for n, s in owns if not n.startswith(maybe_prefix)]
+                owns.append([maybe_prefix, sig])
+                break
+        else:  # iterated completely through owns without any changes
+            break
+
+    sigs = {}
+    for name, sig in owns:
+        sigs.setdefault(sig, []).append(name)
+
+    return json.dumps(sigs, sort_keys=True, indent=True)
+
+
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('--history', action='store_true', help='Generate test list from result history.')
     parser.add_argument('--user', help='User to assign new tests to (or RANDOM, default: current GitHub user).')
     parser.add_argument('--addonly', action='store_true', help='Only add missing tests, do not change existing.')
     parser.add_argument('--check', action='store_true', help='Exit with a nonzero status if the test list has changed.')
+    parser.add_argument('--print_sig_prefixes', action='store_true', help='Emit SIG prefixes for matching.')
     options = parser.parse_args()
 
     if options.history:
@@ -139,6 +172,15 @@ def main():
     test_names = sorted(test_names)
     owners = load_owners(OWNERS_PATH)
 
+    prefixes = sig_prefixes(owners)
+
+    with open(OWNERS_JSON_PATH, 'w') as f:
+        f.write(prefixes + '\n')
+
+    if options.print_sig_prefixes:
+        print prefixes
+        return
+
     outdated_tests = sorted(set(owners) - set(test_names))
     new_tests = sorted(set(test_names) - set(owners))
     maintainers = get_maintainers()
diff --git a/test/test_owners.csv b/test/test_owners.csv
index a2be215ff50..c51a6450929 100644
--- a/test/test_owners.csv
+++ b/test/test_owners.csv
@@ -123,7 +123,7 @@ Empty starts a pod,childsb,1,
 "EmptyDir volumes should support (non-root,0644,default)",timstclair,1,node
 "EmptyDir volumes should support (non-root,0644,tmpfs)",spxtr,1,node
 "EmptyDir volumes should support (non-root,0666,default)",dchen1107,1,node
-"EmptyDir volumes should support (non-root,0666,tmpfs)",apelisse,1,storage
+"EmptyDir volumes should support (non-root,0666,tmpfs)",apelisse,1,node
 "EmptyDir volumes should support (non-root,0777,default)",mwielgus,1,node
 "EmptyDir volumes should support (non-root,0777,tmpfs)",smarterclayton,1,node
 "EmptyDir volumes should support (root,0644,default)",mtaufen,1,node
diff --git a/test/test_owners.json b/test/test_owners.json
new file mode 100644
index 00000000000..86862b5dc3c
--- /dev/null
+++ b/test/test_owners.json
@@ -0,0 +1,124 @@
+{
+ "api-machinery": [
+  "Etcd", 
+  "Generated", 
+  "HA-master", 
+  "Multi-AZ", 
+  "Namespaces", 
+  "ResourceQuota", 
+  "Staging", 
+  "Summary", 
+  "ThirdParty"
+ ], 
+ "apps": [
+  "Cassandra", 
+  "ConfigMap", 
+  "CronJob", 
+  "Daemon", 
+  "Deployment", 
+  "Job", 
+  "Mesos", 
+  "Pet", 
+  "Redis", 
+  "ReplicaSet", 
+  "ReplicationController", 
+  "Rescheduler", 
+  "RethinkDB", 
+  "Secret", 
+  "Security", 
+  "Spark", 
+  "StatefulSet", 
+  "Storm"
+ ], 
+ "autoscaling": [
+  "Cluster size", 
+  "Horizontal"
+ ], 
+ "big-data": [
+  "Hazelcast"
+ ], 
+ "cli": [
+  "Kubectl"
+ ], 
+ "cluster-lifecycle": [
+  "GKE node", 
+  "Garbage", 
+  "Nodes", 
+  "Upgrade"
+ ], 
+ "federation": [
+  "Federated", 
+  "Federation"
+ ], 
+ "instrumentation": [
+  "Cluster level", 
+  "Kibana", 
+  "MetricsGrabber", 
+  "Monitoring"
+ ], 
+ "network": [
+  "ClusterDns", 
+  "DNS", 
+  "ESIPP", 
+  "Firewall", 
+  "Load", 
+  "Network", 
+  "Service"
+ ], 
+ "node": [
+  "AppArmor", 
+  "Cadvisor", 
+  "Container", 
+  "Docker", 
+  "Downward", 
+  "EmptyDir", 
+  "Events", 
+  "HostPath", 
+  "ImageID", 
+  "InitContainer", 
+  "Initial", 
+  "Kubelet", 
+  "LimitRange", 
+  "Liveness", 
+  "Logging", 
+  "MemoryEviction", 
+  "MirrorPod", 
+  "NodeOutOfDisk", 
+  "NodeProblemDetector", 
+  "Opaque", 
+  "Pod garbage", 
+  "Pods", 
+  "Port", 
+  "PreStop", 
+  "PrivilegedPod", 
+  "Probing", 
+  "Proxy", 
+  "Reboot", 
+  "Restart", 
+  "SimpleMount", 
+  "Sysctls", 
+  "Variable", 
+  "kubelet", 
+  "when"
+ ], 
+ "scalability": [
+  "Density"
+ ], 
+ "scheduling": [
+  "DisruptionController", 
+  "NoExecuteTaintManager", 
+  "SchedulerPredicates"
+ ], 
+ "storage": [
+  "Dynamic", 
+  "GCP", 
+  "GKE local", 
+  "PersistentVolumes", 
+  "Pod Disks", 
+  "Projected", 
+  "Volume"
+ ], 
+ "ui": [
+  "Kubernetes"
+ ]
+}