diff --git a/app/controllers/user_classification_count_controller.rb b/app/controllers/user_classification_count_controller.rb
index bcce57a..c3c170a 100644
--- a/app/controllers/user_classification_count_controller.rb
+++ b/app/controllers/user_classification_count_controller.rb
@@ -5,6 +5,11 @@ class UserClassificationCountController < ApplicationController
   before_action :sanitize_params
   before_action :require_login
 
+  PROJ_CONTRIBUTIONS_ORDER_OPTIONS = {
+    recents: 'recents',
+    count: 'count'
+  }.freeze
+
   def query
     current_user['queried_user_id'] = params[:id]
     authorize :queried_user_context, :show?
@@ -17,6 +22,11 @@ def query
   def validate_params
     super
     raise ValidationError, 'Cannot query for project contributions and query by project/workflow' if params[:project_contributions] && (params[:workflow_id] || params[:project_id])
+    validate_order_proj_contributions if params[:order_project_contributions_by]
+  end
+
+  def validate_order_proj_contributions
+    raise ValidationError, 'Can only order project contributions by recents or count. Default behavior is count' unless PROJ_CONTRIBUTIONS_ORDER_OPTIONS.keys.include? params[:order_project_contributions_by].downcase.to_sym
   end
 
   def sanitize_params
@@ -27,10 +37,11 @@ def sanitize_params
   def serializer_opts_from_params
     { period: params[:period],
       time_spent: params[:time_spent],
-      project_contributions: params[:project_contributions] }
+      project_contributions: params[:project_contributions],
+      order_project_contributions_by: params[:order_project_contributions_by] }
   end
 
   def user_classification_count_params
-    params.permit(:id, :start_date, :end_date, :period, :workflow_id, :project_id, :project_contributions, :time_spent)
+    params.permit(:id, :start_date, :end_date, :period, :workflow_id, :project_id, :project_contributions, :time_spent, :order_project_contributions_by)
   end
 end
diff --git a/app/serializers/user_classification_counts_serializer.rb b/app/serializers/user_classification_counts_serializer.rb
index ff92905..f0480ff 100644
--- a/app/serializers/user_classification_counts_serializer.rb
+++ b/app/serializers/user_classification_counts_serializer.rb
@@ -11,16 +11,22 @@ def as_json(options)
     serializer_options = options[:serializer_options]
     show_time_spent = serializer_options[:time_spent]
     show_project_contributions = serializer_options[:project_contributions]
+    order_project_contributions_by = serializer_options[:order_project_contributions_by]
+
     total_count = user_classification_counts.sum(&:count).to_i
     response = { total_count: }
     calculate_time_spent(user_classification_counts, response) if show_time_spent
-    response[:project_contributions] = project_contributions if show_project_contributions
+    response[:project_contributions] = project_contributions(order_project_contributions_by) if show_project_contributions
     response[:data] = response_data(user_classification_counts, show_project_contributions:, show_time_spent:) if serializer_options[:period]
     response
   end
 
   private
 
+  def order_project_contributions_by_recents?(order_project_contributions_by)
+    order_project_contributions_by && order_project_contributions_by.downcase == 'recents'
+  end
+
   def calculate_time_spent(counts, response)
     total_time_spent = counts.sum(&:session_time).to_f
     response[:time_spent] = total_time_spent
@@ -48,10 +54,19 @@ def response_data(user_counts, show_project_contributions:, show_time_spent:)
     end
   end
 
-  def project_contributions
+  def project_contributions(order_by)
     project_contributions = @user_classification_counts.group_by(&:project_id).transform_values do |counts|
       counts.sum(&:count)
     end
-    project_contributions.map { |project_id, count| { project_id:, count: } }.sort_by { |proj_contribution| proj_contribution[:count] }.reverse
+
+    if order_project_contributions_by_recents?(order_by)
+      period_to_contributed_project_ids = @user_classification_counts.sort_by(&:period).reverse.group_by(&:period).transform_values do |uccs|
+        uccs.map(&:project_id)
+      end
+      recently_contributed_project_ids = period_to_contributed_project_ids.values.flatten.uniq
+      recently_contributed_project_ids.map { |project_id| { project_id: , count: project_contributions[project_id] } }
+    else
+      project_contributions.map { |project_id, count| { project_id:, count: } }.sort_by { |proj_contribution| proj_contribution[:count] }.reverse
+    end
   end
 end
diff --git a/spec/controllers/user_classification_count_controller_spec.rb b/spec/controllers/user_classification_count_controller_spec.rb
index 0f3aa54..aed046f 100644
--- a/spec/controllers/user_classification_count_controller_spec.rb
+++ b/spec/controllers/user_classification_count_controller_spec.rb
@@ -126,6 +126,24 @@
         get :query, params: { id: 1, time_spent: 'true' }
         expect(controller.params[:time_spent]).to eq(true)
       end
+
+      context 'order_project_contributions validations' do
+        it 'errors if not a valid order_project_contributions_by option' do
+          get :query, params: { id: 1, order_project_contributions_by: 'blank' }
+          expect(response.status).to eq(400)
+          expect(response.body).to include('Can only order project contributions by recents or count')
+        end
+
+        it 'allows allowable order_project_contributions_by option' do
+          get :query, params: { id: 1, order_project_contributions_by: 'recents' }
+          expect(response.status).to eq(200)
+        end
+
+        it 'allows order_project_contributions_by to be case-insensitive' do
+          get :query, params: { id: 1, order_project_contributions_by: 'COUNT' }
+          expect(response.status).to eq(200)
+        end
+      end
     end
   end
 end
diff --git a/spec/serializers/user_classification_counts_serializer_spec.rb b/spec/serializers/user_classification_counts_serializer_spec.rb
index a3fce9a..b31a866 100644
--- a/spec/serializers/user_classification_counts_serializer_spec.rb
+++ b/spec/serializers/user_classification_counts_serializer_spec.rb
@@ -59,7 +59,7 @@
     let(:user_diff_period_classification_count) { build(:user_diff_period_classification_count) }
     let(:serializer) { described_class.new([user_diff_period_classification_count, user_classification_count, user_diff_proj_count]) }
 
-    it 'shows project_contributions ordered desc by count' do
+    it 'shows project_contributions ordered desc by count when order_proj_contribution_by by not given' do
       serialized = serializer.as_json(serializer_options: { project_contributions: true })
       expect(serialized[:project_contributions].length).to eq(2)
       expect(serialized[:project_contributions][0][:project_id]).to eq(user_classification_count.project_id)
@@ -68,7 +68,29 @@
       expect(serialized[:project_contributions][1][:count]).to eq(user_diff_proj_count.count)
     end
 
-    it 'shows response data bucketed by period when querying top_projects' do
+    context 'when order_project_contributions_by param is given' do
+      it 'shows project_contributions ordered desc by count when order_proj_contribution_by is count' do
+        serialized = serializer.as_json(serializer_options: { project_contributions: true, order_project_contributions_by: 'count' })
+        expect(serialized[:project_contributions].length).to eq(2)
+        expect(serialized[:project_contributions][0][:project_id]).to eq(user_classification_count.project_id)
+        expect(serialized[:project_contributions][0][:count]).to eq(user_classification_count.count + user_diff_period_classification_count.count)
+        expect(serialized[:project_contributions][1][:project_id]).to eq(user_diff_proj_count.project_id)
+        expect(serialized[:project_contributions][1][:count]).to eq(user_diff_proj_count.count)
+      end
+
+      it 'shows project_contributions ordered by recents when order_proj_contribution_by is recents' do
+        classification_count_diff_project_created_yesterday = build(:user_diff_proj_classification_count, period: Date.today - 1)
+        serializer = described_class.new([classification_count_diff_project_created_yesterday, user_classification_count])
+        serialized = serializer.as_json(serializer_options: { project_contributions: true, order_project_contributions_by: 'recents' })
+        expect(serialized[:project_contributions].length).to eq(2)
+        expect(serialized[:project_contributions][0][:project_id]).to eq(user_classification_count.project_id)
+        expect(serialized[:project_contributions][0][:count]).to eq(user_classification_count.count)
+        expect(serialized[:project_contributions][1][:project_id]).to eq(classification_count_diff_project_created_yesterday.project_id)
+        expect(serialized[:project_contributions][1][:count]).to eq(classification_count_diff_project_created_yesterday.count)
+      end
+    end
+
+    it 'shows response data bucketed by period when querying project_contributions by count' do
       serialized = serializer.as_json(serializer_options: { project_contributions: true, period: 'day' })
       expect(serialized[:data].length).to eq(2)
       expect(serialized[:data][0][:period]).to eq(user_diff_period_classification_count.period)