diff --git a/cluster/gce/upgrade.sh b/cluster/gce/upgrade.sh
index 08fbfd55bf357..2dadc1e6bf20b 100755
--- a/cluster/gce/upgrade.sh
+++ b/cluster/gce/upgrade.sh
@@ -174,7 +174,6 @@ function upgrade-nodes() {
 #
 # Vars set:
 #   SANITIZED_VERSION
-#   INSTANCE_GROUPS
 #   KUBELET_TOKEN
 #   KUBE_PROXY_TOKEN
 #   CA_CERT_BASE64
@@ -185,7 +184,7 @@ function prepare-node-upgrade() {
   echo "== Preparing node upgrade (to ${KUBE_VERSION}). ==" >&2
   SANITIZED_VERSION=$(echo ${KUBE_VERSION} | sed 's/[\.\+]/-/g')
 
-  detect-node-names # sets INSTANCE_GROUPS
+  detect-node-names
 
   # TODO(zmerlynn): Refactor setting scope flags.
   local scope_flags=
@@ -232,18 +231,16 @@ function do-node-upgrade() {
     subgroup="alpha compute"
   fi
   local template_name=$(get-template-name-from-version ${SANITIZED_VERSION})
-  for group in ${INSTANCE_GROUPS[@]}; do
-    gcloud ${subgroup} rolling-updates \
-        --project="${PROJECT}" \
-        --zone="${ZONE}" \
-        start \
-        --group="${group}" \
-        --template="${template_name}" \
-        --instance-startup-timeout=300s \
-        --max-num-concurrent-instances=1 \
-        --max-num-failed-instances=0 \
-        --min-instance-update-time=0s
-  done
+  gcloud ${subgroup} rolling-updates \
+      --project="${PROJECT}" \
+      --zone="${ZONE}" \
+      start \
+      --group="${NODE_INSTANCE_PREFIX}-group" \
+      --template="${template_name}" \
+      --instance-startup-timeout=300s \
+      --max-num-concurrent-instances=1 \
+      --max-num-failed-instances=0 \
+      --min-instance-update-time=0s
 
   # TODO(zmerlynn): Wait for the rolling-update to finish.
 
diff --git a/cluster/gce/util.sh b/cluster/gce/util.sh
index b9b4b75ef3cbc..79fb621aa6dec 100755
--- a/cluster/gce/util.sh
+++ b/cluster/gce/util.sh
@@ -253,24 +253,12 @@ function upload-server-tars() {
 #   NODE_INSTANCE_PREFIX
 # Vars set:
 #   NODE_NAMES
-#   INSTANCE_GROUPS
 function detect-node-names {
   detect-project
-  INSTANCE_GROUPS=()
-  INSTANCE_GROUPS+=($(gcloud compute instance-groups managed list --zone "${ZONE}" --project "${PROJECT}" | grep ${NODE_INSTANCE_PREFIX} | cut -f1 -d" "))
-  NODE_NAMES=()
-  if [[ -n "${INSTANCE_GROUPS[@]:-}" ]]; then
-    for group in "${INSTANCE_GROUPS[@]}"; do
-      NODE_NAMES+=($(gcloud compute instance-groups managed list-instances \
-        "${group}" --zone "${ZONE}" --project "${PROJECT}" \
-        --format=yaml | grep instance: | cut -d ' ' -f 2))
-    done
-    echo "INSTANCE_GROUPS=${INSTANCE_GROUPS[*]}" >&2
-    echo "NODE_NAMES=${NODE_NAMES[*]}" >&2
-  else 
-    echo "INSTANCE_GROUPS=" >&2
-    echo "NODE_NAMES=" >&2
-  fi
+  NODE_NAMES=($(gcloud compute instance-groups managed list-instances \
+    "${NODE_INSTANCE_PREFIX}-group" --zone "${ZONE}" --project "${PROJECT}" \
+    --format=yaml | grep instance: | cut -d ' ' -f 2))
+  echo "NODE_NAMES=${NODE_NAMES[*]}" >&2
 }
 
 # Detect the information about the minions
@@ -725,43 +713,17 @@ function kube-up {
   
   create-node-instance-template $template_name
 
-  local defaulted_max_instances_per_mig=${MAX_INSTANCES_PER_MIG:-500}
-
-  if [[ ${defaulted_max_instances_per_mig} -le "0" ]]; then
-    echo "MAX_INSTANCES_PER_MIG cannot be negative. Assuming default 500"
-    defaulted_max_instances_per_mig=500
-  fi
-  local num_migs=$(((${NUM_NODES} + ${defaulted_max_instances_per_mig} - 1) / ${defaulted_max_instances_per_mig}))
-  local instances_per_mig=$(((${NUM_NODES} + ${num_migs} - 1) / ${num_migs}))
-  local last_mig_size=$((${NUM_NODES} - (${num_migs} - 1) * ${instances_per_mig}))
-
-  #TODO: parallelize this loop to speed up the process
-  for i in $(seq $((${num_migs} - 1))); do
-    gcloud compute instance-groups managed \
-        create "${NODE_INSTANCE_PREFIX}-group-$i" \
-        --project "${PROJECT}" \
-        --zone "${ZONE}" \
-        --base-instance-name "${NODE_INSTANCE_PREFIX}" \
-        --size "${instances_per_mig}" \
-        --template "$template_name" || true;
-    gcloud compute instance-groups managed wait-until-stable \
-        "${NODE_INSTANCE_PREFIX}-group-$i" \
-	      --zone "${ZONE}" \
-	      --project "${PROJECT}" || true;
-  done
-
   gcloud compute instance-groups managed \
-      create "${NODE_INSTANCE_PREFIX}-group-${num_migs}" \
+      create "${NODE_INSTANCE_PREFIX}-group" \
       --project "${PROJECT}" \
       --zone "${ZONE}" \
       --base-instance-name "${NODE_INSTANCE_PREFIX}" \
-      --size "${last_mig_size}" \
+      --size "${NUM_NODES}" \
       --template "$template_name" || true;
   gcloud compute instance-groups managed wait-until-stable \
-      "${NODE_INSTANCE_PREFIX}-group-${num_migs}" \
-      --zone "${ZONE}" \
-      --project "${PROJECT}" || true;
-
+      "${NODE_INSTANCE_PREFIX}-group" \
+			--zone "${ZONE}" \
+			--project "${PROJECT}" || true;
   detect-node-names
   detect-master
 
@@ -780,12 +742,9 @@ function kube-up {
     METRICS+="--custom-metric-utilization metric=custom.cloudmonitoring.googleapis.com/kubernetes.io/memory/node_reservation,"
     METRICS+="utilization-target=${TARGET_NODE_UTILIZATION},utilization-target-type=GAUGE "
 
-    echo "Creating node autoscalers."
-
-    for i in $(seq ${num_migs}); do
-      gcloud compute instance-groups managed set-autoscaling "${NODE_INSTANCE_PREFIX}-group-$i" --zone "${ZONE}" --project "${PROJECT}" \
-          --min-num-replicas "${AUTOSCALER_MIN_NODES}" --max-num-replicas "${AUTOSCALER_MAX_NODES}" ${METRICS} || true
-    done
+    echo "Creating node autoscaler."
+    gcloud compute instance-groups managed set-autoscaling "${NODE_INSTANCE_PREFIX}-group" --zone "${ZONE}" --project "${PROJECT}" \
+        --min-num-replicas "${AUTOSCALER_MIN_NODES}" --max-num-replicas "${AUTOSCALER_MAX_NODES}" ${METRICS} || true
   fi
 
   echo "Waiting up to ${KUBE_CLUSTER_INITIALIZATION_TIMEOUT} seconds for cluster initialization."
@@ -851,51 +810,46 @@ function kube-up {
 # down the firewall rules and routes.
 function kube-down {
   detect-project
-  detect-node-names # For INSTANCE_GROUPS
 
   echo "Bringing down cluster"
   set +e  # Do not stop on error
 
-  # Delete autoscaler for nodes if present. We assume that all or none instance groups have an autoscaler
+  # Delete autoscaler for nodes if present.
   local autoscaler
   autoscaler=( $(gcloud compute instance-groups managed list --zone "${ZONE}" --project "${PROJECT}" \
-                 | grep "${NODE_INSTANCE_PREFIX}-group-1" \
+                 | grep "${NODE_INSTANCE_PREFIX}-group" \
                  | awk '{print $7}') )
   if [[ "${autoscaler:-}" == "yes" ]]; then
-    for group in ${INSTANCE_GROUPS[@]}; do
-      gcloud compute instance-groups managed stop-autoscaling "${group}" --zone "${ZONE}" --project "${PROJECT}"
-    done
+    gcloud compute instance-groups managed stop-autoscaling "${NODE_INSTANCE_PREFIX}-group" --zone "${ZONE}" --project "${PROJECT}"
   fi
 
   # Get the name of the managed instance group template before we delete the
   # managed instange group. (The name of the managed instnace group template may
   # change during a cluster upgrade.)
-  local template=$(get-template "${PROJECT}" "${ZONE}" "${NODE_INSTANCE_PREFIX}-group-1")
+  local template=$(get-template "${PROJECT}" "${ZONE}" "${NODE_INSTANCE_PREFIX}-group")
 
   # The gcloud APIs don't return machine parseable error codes/retry information. Therefore the best we can
   # do is parse the output and special case particular responses we are interested in.
-  for group in ${INSTANCE_GROUPS[@]}; do 
-    if gcloud compute instance-groups managed describe "${group}" --project "${PROJECT}" --zone "${ZONE}" &>/dev/null; then
-      deleteCmdOutput=$(gcloud compute instance-groups managed delete --zone "${ZONE}" \
-        --project "${PROJECT}" \
-        --quiet \
-        "${group}")
-      if [[ "$deleteCmdOutput" != ""  ]]; then
-        # Managed instance group deletion is done asynchronously, we must wait for it to complete, or subsequent steps fail
-        deleteCmdOperationId=$(echo $deleteCmdOutput | grep "Operation:" | sed "s/.*Operation:[[:space:]]*\([^[:space:]]*\).*/\1/g")
-        if [[ "$deleteCmdOperationId" != ""  ]]; then
-          deleteCmdStatus="PENDING"
-          while [[ "$deleteCmdStatus" != "DONE" ]]
-          do
-            sleep 5
-            deleteCmdOperationOutput=$(gcloud compute instance-groups managed --zone "${ZONE}" --project "${PROJECT}" get-operation $deleteCmdOperationId)
-            deleteCmdStatus=$(echo $deleteCmdOperationOutput | grep -i "status:" | sed "s/.*status:[[:space:]]*\([^[:space:]]*\).*/\1/g")
-            echo "Waiting for MIG deletion to complete. Current status: " $deleteCmdStatus
-          done
-        fi
+  if gcloud compute instance-groups managed describe "${NODE_INSTANCE_PREFIX}-group" --project "${PROJECT}" --zone "${ZONE}" &>/dev/null; then
+    deleteCmdOutput=$(gcloud compute instance-groups managed delete --zone "${ZONE}" \
+      --project "${PROJECT}" \
+      --quiet \
+      "${NODE_INSTANCE_PREFIX}-group")
+    if [[ "$deleteCmdOutput" != ""  ]]; then
+      # Managed instance group deletion is done asynchronously, we must wait for it to complete, or subsequent steps fail
+      deleteCmdOperationId=$(echo $deleteCmdOutput | grep "Operation:" | sed "s/.*Operation:[[:space:]]*\([^[:space:]]*\).*/\1/g")
+      if [[ "$deleteCmdOperationId" != ""  ]]; then
+        deleteCmdStatus="PENDING"
+        while [[ "$deleteCmdStatus" != "DONE" ]]
+        do
+          sleep 5
+          deleteCmdOperationOutput=$(gcloud compute instance-groups managed --zone "${ZONE}" --project "${PROJECT}" get-operation $deleteCmdOperationId)
+          deleteCmdStatus=$(echo $deleteCmdOperationOutput | grep -i "status:" | sed "s/.*status:[[:space:]]*\([^[:space:]]*\).*/\1/g")
+          echo "Waiting for MIG deletion to complete. Current status: " $deleteCmdStatus
+        done
       fi
     fi
-  done
+  fi
 
   if gcloud compute instance-templates describe --project "${PROJECT}" "${template}" &>/dev/null; then
     gcloud compute instance-templates delete \
@@ -1028,13 +982,12 @@ function get-template {
 #   KUBE_RESOURCE_FOUND
 function check-resources {
   detect-project
-  detect-node-names
 
   echo "Looking for already existing resources"
   KUBE_RESOURCE_FOUND=""
 
-  if [[ -n "${INSTANCE_GROUPS[@]:-}" ]]; then
-    KUBE_RESOURCE_FOUND="Managed instance groups ${INSTANCE_GROUPS[@]}"
+  if gcloud compute instance-groups managed describe --project "${PROJECT}" --zone "${ZONE}" "${NODE_INSTANCE_PREFIX}-group" &>/dev/null; then
+    KUBE_RESOURCE_FOUND="Managed instance group ${NODE_INSTANCE_PREFIX}-group"
     return 1
   fi
 
@@ -1137,13 +1090,11 @@ function prepare-push() {
     create-node-instance-template $tmp_template_name
 
     local template_name="${NODE_INSTANCE_PREFIX}-template"
-    for group in ${INSTANCE_GROUPS[@]}; do
-      gcloud compute instance-groups managed \
-        set-instance-template "${group}" \
-        --template "$tmp_template_name" \
-        --zone "${ZONE}" \
-        --project "${PROJECT}" || true;
-    done
+    gcloud compute instance-groups managed \
+      set-instance-template "${NODE_INSTANCE_PREFIX}-group" \
+      --template "$tmp_template_name" \
+      --zone "${ZONE}" \
+      --project "${PROJECT}" || true;
 
     gcloud compute instance-templates delete \
       --project "${PROJECT}" \
@@ -1152,13 +1103,11 @@ function prepare-push() {
 
     create-node-instance-template "$template_name"
 
-    for group in ${INSTANCE_GROUPS[@]}; do
-      gcloud compute instance-groups managed \
-        set-instance-template "${group}" \
-        --template "$template_name" \
-        --zone "${ZONE}" \
-        --project "${PROJECT}" || true;
-    done
+    gcloud compute instance-groups managed \
+      set-instance-template "${NODE_INSTANCE_PREFIX}-group" \
+      --template "$template_name" \
+      --zone "${ZONE}" \
+      --project "${PROJECT}" || true;
 
     gcloud compute instance-templates delete \
       --project "${PROJECT}" \