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diff --git a/examples/instance_segmentation/data_annotated/2011_000006.json b/examples/instance_segmentation/data_annotated/2011_000006.json
index 4f291ca26a80d0de42e749f90783c59c9bb44381..ada2df6f81c06e017fd14eaddf70712f1a88e449 100644
--- a/examples/instance_segmentation/data_annotated/2011_000006.json
+++ b/examples/instance_segmentation/data_annotated/2011_000006.json
@@ -1,8 +1,9 @@
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diff --git a/examples/semantic_segmentation/data_annotated/2011_000003.json b/examples/semantic_segmentation/data_annotated/2011_000003.json
index 59bd87afac78644dc6a3768ee652e7f41b59020a..7ff7eb9dd22121d2ba4b378f509b55a807377c44 100644
--- a/examples/semantic_segmentation/data_annotated/2011_000003.json
+++ b/examples/semantic_segmentation/data_annotated/2011_000003.json
@@ -1,9 +1,9 @@
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+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "person",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           482.81422924901193,
@@ -340,12 +341,37 @@
           499.81422924901193,
           90.33596837944665
         ]
-      ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
+    },
+    {
+      "label": "person",
+      "points": [
+        [
+          370.81422924901193,
+          170.33596837944665
+        ],
+        [
+          366.81422924901193,
+          173.33596837944665
+        ],
+        [
+          365.81422924901193,
+          182.33596837944665
+        ],
+        [
+          368.81422924901193,
+          185.33596837944665
+        ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "bottle",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           374.81422924901193,
@@ -383,35 +409,13 @@
           382.81422924901193,
           159.33596837944665
         ]
-      ]
-    },
-    {
-      "label": "person",
-      "line_color": null,
-      "fill_color": null,
-      "points": [
-        [
-          370.81422924901193,
-          170.33596837944665
-        ],
-        [
-          366.81422924901193,
-          173.33596837944665
-        ],
-        [
-          365.81422924901193,
-          182.33596837944665
-        ],
-        [
-          368.81422924901193,
-          185.33596837944665
-        ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "__ignore__",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           338.81422924901193,
@@ -461,9 +465,16 @@
           370.81422924901193,
           270.3359683794467
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     }
   ],
+  "imagePath": "2011_000003.jpg",
+  "imageData": null,
+  "imageHeight": 338,
+  "imageWidth": 500,
   "lineColor": [
     0,
     255,
@@ -475,7 +486,5 @@
     0,
     0,
     128
-  ],
-  "imagePath": "2011_000003.jpg",
-  "imageData": null
+  ]
 }
\ No newline at end of file
diff --git a/examples/semantic_segmentation/data_annotated/2011_000006.json b/examples/semantic_segmentation/data_annotated/2011_000006.json
index fbf3ab6e57535dd55f231481fec4adfd71cea9f4..ada2df6f81c06e017fd14eaddf70712f1a88e449 100644
--- a/examples/semantic_segmentation/data_annotated/2011_000006.json
+++ b/examples/semantic_segmentation/data_annotated/2011_000006.json
@@ -1,9 +1,9 @@
 {
+  "version": "3.22.0",
+  "flags": {},
   "shapes": [
     {
       "label": "person",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           204.936170212766,
@@ -105,12 +105,13 @@
           216.936170212766,
           112.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "person",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           271.936170212766,
@@ -188,12 +189,13 @@
           296.936170212766,
           148.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "person",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           308.936170212766,
@@ -259,12 +261,13 @@
           336.936170212766,
           115.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "chair",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           308.936170212766,
@@ -326,12 +329,13 @@
           350.936170212766,
           241.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "person",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           425.936170212766,
@@ -357,12 +361,13 @@
           446.936170212766,
           91.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "__ignore__",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           457.936170212766,
@@ -380,12 +385,13 @@
           474.936170212766,
           87.56382978723406
         ]
-      ]
+      ],
+      "group_id": null,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "sofa",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           183.936170212766,
@@ -423,12 +429,13 @@
           110.93617021276599,
           203.56382978723406
         ]
-      ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "sofa",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           103.93617021276599,
@@ -442,12 +449,13 @@
           97.93617021276599,
           311.56382978723406
         ]
-      ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "sofa",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           348.936170212766,
@@ -485,12 +493,13 @@
           353.936170212766,
           164.56382978723406
         ]
-      ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
     },
     {
       "label": "sofa",
-      "line_color": null,
-      "fill_color": null,
       "points": [
         [
           246.936170212766,
@@ -508,9 +517,16 @@
           261.936170212766,
           256.56382978723406
         ]
-      ]
+      ],
+      "group_id": 0,
+      "shape_type": "polygon",
+      "flags": {}
     }
   ],
+  "imagePath": "2011_000006.jpg",
+  "imageData": null,
+  "imageHeight": 375,
+  "imageWidth": 500,
   "lineColor": [
     0,
     255,
@@ -522,7 +538,5 @@
     0,
     0,
     128
-  ],
-  "imagePath": "2011_000006.jpg",
-  "imageData": null
+  ]
 }
\ No newline at end of file
diff --git a/labelme/app.py b/labelme/app.py
index 871ed3a425244421b523534132f2f61f5524da6c..07771d97a1a3d37c5c81e32cb87d4b14c32374e1 100644
--- a/labelme/app.py
+++ b/labelme/app.py
@@ -895,7 +895,9 @@ class MainWindow(QtWidgets.QMainWindow):
         shape = self.labelList.get_shape_from_item(item)
         if shape is None:
             return
-        text, flags = self.labelDialog.popUp(shape.label, flags=shape.flags)
+        text, flags, group_id = self.labelDialog.popUp(
+            text=shape.label, flags=shape.flags, group_id=shape.group_id,
+        )
         if text is None:
             return
         if not self.validateLabel(text):
@@ -908,10 +910,14 @@ class MainWindow(QtWidgets.QMainWindow):
             return
         shape.label = text
         shape.flags = flags
-        item.setText(text)
+        shape.group_id = group_id
+        if shape.group_id is None:
+            item.setText(shape.label)
+        else:
+            item.setText('{} ({})'.format(shape.label, shape.group_id))
         self.setDirty()
-        if not self.uniqLabelList.findItems(text, Qt.MatchExactly):
-            self.uniqLabelList.addItem(text)
+        if not self.uniqLabelList.findItems(shape.label, Qt.MatchExactly):
+            self.uniqLabelList.addItem(shape.label)
             self.uniqLabelList.sortItems()
 
     def fileSearchChanged(self):
@@ -955,7 +961,11 @@ class MainWindow(QtWidgets.QMainWindow):
         self.actions.edit.setEnabled(n_selected == 1)
 
     def addLabel(self, shape):
-        item = QtWidgets.QListWidgetItem(shape.label)
+        if shape.group_id is None:
+            text = shape.label
+        else:
+            text = '{} ({})'.format(shape.label, shape.group_id)
+        item = QtWidgets.QListWidgetItem(text)
         item.setFlags(item.flags() | Qt.ItemIsUserCheckable)
         item.setCheckState(Qt.Checked)
         self.labelList.itemsToShapes.append((item, shape))
@@ -963,7 +973,7 @@ class MainWindow(QtWidgets.QMainWindow):
         if not self.uniqLabelList.findItems(shape.label, Qt.MatchExactly):
             self.uniqLabelList.addItem(shape.label)
             self.uniqLabelList.sortItems()
-        self.labelDialog.addLabelHistory(item.text())
+        self.labelDialog.addLabelHistory(shape.label)
         for action in self.actions.onShapesPresent:
             action.setEnabled(True)
 
@@ -987,8 +997,11 @@ class MainWindow(QtWidgets.QMainWindow):
             points = shape['points']
             shape_type = shape['shape_type']
             flags = shape['flags']
+            group_id = shape.get('group_id')
 
-            shape = Shape(label=label, shape_type=shape_type)
+            shape = Shape(
+                label=label, shape_type=shape_type, group_id=group_id
+            )
             for x, y in points:
                 shape.addPoint(QtCore.QPointF(x, y))
             shape.close()
@@ -1020,6 +1033,7 @@ class MainWindow(QtWidgets.QMainWindow):
             return dict(
                 label=s.label.encode('utf-8') if PY2 else s.label,
                 points=[(p.x(), p.y()) for p in s.points],
+                group_id=s.group_id,
                 shape_type=s.shape_type,
                 flags=s.flags
             )
@@ -1127,7 +1141,8 @@ class MainWindow(QtWidgets.QMainWindow):
             text = ''
         if text:
             self.labelList.clearSelection()
-            self.addLabel(self.canvas.setLastLabel(text, flags))
+            shape = self.canvas.setLastLabel(text, flags)
+            self.addLabel(shape)
             self.actions.editMode.setEnabled(True)
             self.actions.undoLastPoint.setEnabled(False)
             self.actions.undo.setEnabled(True)
diff --git a/labelme/label_file.py b/labelme/label_file.py
index eac92f2f77537d09dc1a103a3e63b2c203868e1f..bc32a6ad2725fa85f773dddc47f14ec451295fdf 100644
--- a/labelme/label_file.py
+++ b/labelme/label_file.py
@@ -88,6 +88,7 @@ class LabelFile(object):
                     points=s['points'],
                     shape_type=s.get('shape_type', 'polygon'),
                     flags=s.get('flags', {}),
+                    group_id=s.get('group_id')
                 )
                 for s in data['shapes']
             ]
diff --git a/labelme/shape.py b/labelme/shape.py
index 847c9655fbaea4f7d460af6692b56c5ec89ba262..8a82460c04477afac5819d321a49ee5f3a1aa9ec 100644
--- a/labelme/shape.py
+++ b/labelme/shape.py
@@ -37,8 +37,9 @@ class Shape(object):
     scale = 1.0
 
     def __init__(self, label=None, line_color=None, shape_type=None,
-                 flags=None):
+                 flags=None, group_id=None):
         self.label = label
+        self.group_id = group_id
         self.points = []
         self.fill = False
         self.selected = False
diff --git a/labelme/widgets/label_dialog.py b/labelme/widgets/label_dialog.py
index d163a4def352a271abf1a3034b038760d6513f27..ebbb15eed43fc7c29108ceea80f71547ca527926 100644
--- a/labelme/widgets/label_dialog.py
+++ b/labelme/widgets/label_dialog.py
@@ -43,9 +43,17 @@ class LabelDialog(QtWidgets.QDialog):
         self.edit.editingFinished.connect(self.postProcess)
         if flags:
             self.edit.textChanged.connect(self.updateFlags)
+        self.edit_group_id = QtWidgets.QLineEdit()
+        self.edit_group_id.setPlaceholderText('Group ID')
+        self.edit_group_id.setValidator(
+            QtGui.QRegExpValidator(QtCore.QRegExp(r'\d*'), None)
+        )
         layout = QtWidgets.QVBoxLayout()
         if show_text_field:
-            layout.addWidget(self.edit)
+            layout_edit = QtWidgets.QHBoxLayout()
+            layout_edit.addWidget(self.edit, 6)
+            layout_edit.addWidget(self.edit_group_id, 2)
+            layout.addLayout(layout_edit)
         # buttons
         self.buttonBox = bb = QtWidgets.QDialogButtonBox(
             QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel,
@@ -178,7 +186,13 @@ class LabelDialog(QtWidgets.QDialog):
             flags[item.text()] = item.isChecked()
         return flags
 
-    def popUp(self, text=None, move=True, flags=None):
+    def getGroupId(self):
+        group_id = self.edit_group_id.text()
+        if group_id:
+            return int(group_id)
+        return None
+
+    def popUp(self, text=None, move=True, flags=None, group_id=None):
         if self._fit_to_content['row']:
             self.labelList.setMinimumHeight(
                 self.labelList.sizeHintForRow(0) * self.labelList.count() + 2
@@ -196,6 +210,10 @@ class LabelDialog(QtWidgets.QDialog):
             self.resetFlags(text)
         self.edit.setText(text)
         self.edit.setSelection(0, len(text))
+        if group_id is None:
+            self.edit_group_id.clear()
+        else:
+            self.edit_group_id.setText(str(group_id))
         items = self.labelList.findItems(text, QtCore.Qt.MatchFixedString)
         if items:
             if len(items) != 1:
@@ -207,6 +225,6 @@ class LabelDialog(QtWidgets.QDialog):
         if move:
             self.move(QtGui.QCursor.pos())
         if self.exec_():
-            return self.edit.text(), self.getFlags()
+            return self.edit.text(), self.getFlags(), self.getGroupId()
         else:
-            return None, None
+            return None, None, None
diff --git a/tests/labelme_tests/widgets_tests/test_label_dialog.py b/tests/labelme_tests/widgets_tests/test_label_dialog.py
index 4b1249c6025ede4f0ab5b97c965e27d1b2f09868..65009f17d5ffbffd96178be4ebc09643b7c79559 100644
--- a/tests/labelme_tests/widgets_tests/test_label_dialog.py
+++ b/tests/labelme_tests/widgets_tests/test_label_dialog.py
@@ -59,9 +59,10 @@ def test_LabelDialog_popUp(qtbot):
         qtbot.keyClick(widget.edit, QtCore.Qt.Key_Enter)  # NOQA
 
     QtCore.QTimer.singleShot(500, interact)
-    label, flags = widget.popUp('cat')
+    label, flags, group_id = widget.popUp('cat')
     assert label == 'person'
     assert flags == {}
+    assert group_id is None
 
     # popUp()
 
@@ -70,9 +71,10 @@ def test_LabelDialog_popUp(qtbot):
         qtbot.keyClick(widget.edit, QtCore.Qt.Key_Enter)  # NOQA
 
     QtCore.QTimer.singleShot(500, interact)
-    label, flags = widget.popUp()
+    label, flags, group_id = widget.popUp()
     assert label == 'person'
     assert flags == {}
+    assert group_id is None
 
     # popUp() + key_Up
 
@@ -82,6 +84,7 @@ def test_LabelDialog_popUp(qtbot):
         qtbot.keyClick(widget.edit, QtCore.Qt.Key_Enter)  # NOQA
 
     QtCore.QTimer.singleShot(500, interact)
-    label, flags = widget.popUp()
+    label, flags, group_id = widget.popUp()
     assert label == 'dog'
     assert flags == {}
+    assert group_id is None