diff --git a/lib/tasks/correct_has_other_client_group_values.rake b/lib/tasks/correct_has_other_client_group_values.rake
new file mode 100644
index 000000000..1ee51a5e4
--- /dev/null
+++ b/lib/tasks/correct_has_other_client_group_values.rake
@@ -0,0 +1,5 @@
+desc "Update has_other_client_group values for schemes"
+task correct_has_other_client_group_values: :environment do
+  Scheme.where(confirmed: true, secondary_client_group: nil).update_all(has_other_client_group: 0)
+  Scheme.where(confirmed: true).where.not(secondary_client_group: nil).update_all(has_other_client_group: 1)
+end
diff --git a/spec/lib/tasks/correct_has_other_client_group_values_spec.rb b/spec/lib/tasks/correct_has_other_client_group_values_spec.rb
new file mode 100644
index 000000000..9e021b05e
--- /dev/null
+++ b/spec/lib/tasks/correct_has_other_client_group_values_spec.rb
@@ -0,0 +1,56 @@
+require "rails_helper"
+require "rake"
+
+RSpec.describe "correct_has_other_client_group_values" do
+  describe ":correct_has_other_client_group_values", type: :task do
+    subject(:task) { Rake::Task["correct_has_other_client_group_values"] }
+
+    before do
+      Rake.application.rake_require("tasks/correct_has_other_client_group_values")
+      Rake::Task.define_task(:environment)
+      task.reenable
+    end
+
+    context "when the rake task is run" do
+      let!(:scheme) { create(:scheme, secondary_client_group: nil) }
+
+      before do
+        scheme.has_other_client_group = nil
+        scheme.save!(validate: false)
+      end
+
+      context "and the scheme is marked confirmed" do
+        it "updates schemes with secondary_client_group to have has_other_client_group 1 (yes)" do
+          scheme.secondary_client_group = "G"
+          scheme.save!(validate: false)
+          task.invoke
+          expect(scheme.reload.has_other_client_group).to eq("Yes")
+        end
+
+        it "updates schemes without secondary_client_group to have has_other_client_group 0 (no)" do
+          task.invoke
+          expect(scheme.reload.has_other_client_group).to eq("No")
+        end
+      end
+
+      context "and the scheme is not marked confirmed" do
+        before do
+          scheme.confirmed = false
+          scheme.save!(validate: false)
+        end
+
+        it "does not update schemes with secondary_client_group" do
+          scheme.secondary_client_group = "G"
+          scheme.save!(validate: false)
+          task.invoke
+          expect(scheme.reload.has_other_client_group).to eq(nil)
+        end
+
+        it "does not update schemes without secondary_client_group" do
+          task.invoke
+          expect(scheme.reload.has_other_client_group).to eq(nil)
+        end
+      end
+    end
+  end
+end