diff --git a/app/models/administrateur.rb b/app/models/administrateur.rb
index a35e77098..d6bbbe258 100644
--- a/app/models/administrateur.rb
+++ b/app/models/administrateur.rb
@@ -12,6 +12,8 @@
 class Administrateur < ApplicationRecord
   include ActiveRecord::SecureToken
 
+  UNUSED_ADMIN_THRESHOLD = 6.months
+
   has_and_belongs_to_many :instructeurs
   has_and_belongs_to_many :procedures
   has_many :services
@@ -23,6 +25,14 @@ class Administrateur < ApplicationRecord
   scope :inactive, -> { joins(:user).where(users: { last_sign_in_at: nil }) }
   scope :with_publiees_ou_closes, -> { joins(:procedures).where(procedures: { aasm_state: [:publiee, :close, :depubliee] }) }
 
+  scope :unused, -> do
+    joins(:user)
+      .where.missing(:services)
+      .left_outer_joins(:administrateurs_procedures) # needed to bypass procedure hidden default scope
+      .where(administrateurs_procedures: { procedure_id: nil })
+      .where("users.last_sign_in_at < ? ", UNUSED_ADMIN_THRESHOLD.ago)
+  end
+
   def self.by_email(email)
     Administrateur.find_by(users: { email: email })
   end
diff --git a/spec/models/administrateur_spec.rb b/spec/models/administrateur_spec.rb
index ce21fb67a..9da4b2c0c 100644
--- a/spec/models/administrateur_spec.rb
+++ b/spec/models/administrateur_spec.rb
@@ -163,4 +163,34 @@ describe Administrateur, type: :model do
       end
     end
   end
+
+  describe 'unused' do
+    subject { Administrateur.unused }
+
+    let(:new_admin) { create(:administrateur) }
+    let(:unused_admin) { create(:administrateur) }
+
+    before do
+      new_admin.user.update(last_sign_in_at: (6.months - 1.day).ago)
+      unused_admin.user.update(last_sign_in_at: (6.months + 1.day).ago)
+    end
+
+    it { is_expected.to match([unused_admin]) }
+
+    context 'with a hidden procedure' do
+      let(:procedure) { create(:procedure, hidden_at: 1.month.ago) }
+
+      before { unused_admin.procedures << procedure }
+
+      it { is_expected.to be_empty }
+    end
+
+    context 'with a service' do
+      let(:service) { create(:service) }
+
+      before { unused_admin.services << service }
+
+      it { is_expected.to be_empty }
+    end
+  end
 end