diff --git a/backend/api/filters.py b/backend/api/filters.py
index 8dc1f484..cdd02b1e 100644
--- a/backend/api/filters.py
+++ b/backend/api/filters.py
@@ -31,3 +31,25 @@ class DocumentFilter(FilterSet):
             'categories__label__id', 'spans__label__id',
             'categories__isnull', 'spans__isnull', 'texts__isnull'
         )
+
+
+class ExampleFilter(FilterSet):
+    confirmed = BooleanFilter(field_name='states', method='filter_by_state')
+
+    def filter_by_state(self, queryset, field_name, is_confirmed: bool):
+        queryset = queryset.annotate(
+            num_confirm=Count(
+                expression=field_name,
+                filter=Q(**{f'{field_name}__confirmed_by': self.request.user}) |
+                Q(project__collaborative_annotation=True)
+            )
+        )
+        if is_confirmed:
+            queryset = queryset.filter(num_confirm__gte=1)
+        else:
+            queryset = queryset.filter(num_confirm__lte=0)
+        return queryset
+
+    class Meta:
+        model = Example
+        fields = ('project', 'text', 'created_at', 'updated_at')
diff --git a/backend/api/tests/test_filters.py b/backend/api/tests/test_filters.py
new file mode 100644
index 00000000..4c8d6312
--- /dev/null
+++ b/backend/api/tests/test_filters.py
@@ -0,0 +1,77 @@
+from unittest.mock import MagicMock
+
+from django.test import TestCase
+
+from ..filters import ExampleFilter
+from ..models import Example
+from .api.utils import make_doc, make_example_state, prepare_project
+
+
+class TestFilterMixin(TestCase):
+
+    def prepare(self, project):
+        self.example = make_doc(project.item)
+        self.request = MagicMock()
+        self.queryset = Example.objects.all()
+        make_example_state(self.example, project.users[0])
+        self.request.user = project.users[0]
+
+    def assert_filter(self, data, expected):
+        f = ExampleFilter(
+            data=data,
+            queryset=self.queryset,
+            request=self.request
+        )
+        self.assertEqual(f.qs.count(), expected)
+
+
+class TestExampleFilter(TestFilterMixin):
+
+    def setUp(self):
+        self.project = prepare_project(task='DocumentClassification')
+        self.prepare(project=self.project)
+
+    def test_returns_example_if_confirmed_is_true(self):
+        self.assert_filter(data={'confirmed': 'True'}, expected=1)
+
+    def test_does_not_return_example_if_confirmed_is_false(self):
+        self.assert_filter(data={'confirmed': 'False'}, expected=0)
+
+    def test_returns_example_if_confirmed_is_empty(self):
+        self.assert_filter(data={'confirmed': ''}, expected=1)
+
+    def test_does_not_return_example_if_user_is_different(self):
+        self.request.user = self.project.users[1]
+        self.assert_filter(data={'confirmed': 'True'}, expected=0)
+
+    def test_returns_example_if_user_is_different(self):
+        self.request.user = self.project.users[1]
+        self.assert_filter(data={'confirmed': 'False'}, expected=1)
+
+    def test_returns_example_if_user_is_different_and_confirmed_is_empty(self):
+        self.request.user = self.project.users[1]
+        self.assert_filter(data={'confirmed': ''}, expected=1)
+
+
+class TestExampleFilterOnCollaborative(TestFilterMixin):
+
+    def setUp(self):
+        self.project = prepare_project(
+            task='DocumentClassification', collaborative_annotation=True
+        )
+        self.prepare(project=self.project)
+
+    def test_returns_example_if_confirmed_is_true(self):
+        for member in self.project.users:
+            self.request.user = member
+            self.assert_filter(data={'confirmed': 'True'}, expected=1)
+
+    def test_does_not_return_example_if_confirmed_is_false(self):
+        for member in self.project.users:
+            self.request.user = member
+            self.assert_filter(data={'confirmed': 'False'}, expected=0)
+
+    def test_returns_example_if_confirmed_is_empty(self):
+        for member in self.project.users:
+            self.request.user = member
+            self.assert_filter(data={'confirmed': ''}, expected=1)