diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5637083df..aea55c771e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+## Unreleased
+- Add complete plan flag to V2 API [#3595](https://github.com/DMPRoadmap/roadmap/pull/3595)
+
 ## v5.0.2
 - Bump Ruby to v3.1.4 and use `.ruby-version` in CI
   - [#3566](https://github.com/DMPRoadmap/roadmap/pull/3566)
diff --git a/app/controllers/api/v2/plans_controller.rb b/app/controllers/api/v2/plans_controller.rb
index 7714e9c892..a12635c585 100644
--- a/app/controllers/api/v2/plans_controller.rb
+++ b/app/controllers/api/v2/plans_controller.rb
@@ -4,12 +4,13 @@ module Api
   module V2
     class PlansController < BaseApiController # rubocop:todo Style/Documentation
       respond_to :json
+      before_action :set_complete_param, only: %i[show index]
 
       # GET /api/v2/plans/:id
       def show
         raise Pundit::NotAuthorizedError unless @scopes.include?('read')
 
-        @plan = Plan.find_by(id: params[:id])
+        @plan = Plan.includes(roles: :user).find_by(id: params[:id])
 
         raise Pundit::NotAuthorizedError unless @plan.present?
 
@@ -25,9 +26,17 @@ def index
         raise Pundit::NotAuthorizedError unless @scopes.include?('read')
 
         @plans = PlansPolicy::Scope.new(@resource_owner).resolve
+        @plans = @plans.includes(answers: { question: :section }) if @complete
         @items = paginate_response(results: @plans)
         render '/api/v2/plans/index', status: :ok
       end
+
+      private
+
+      # GET /api/v2/plans?complete=true and  /api/v2/plans/:id?complete=true
+      def set_complete_param
+        @complete = params[:complete].to_s.downcase == 'true'
+      end
     end
   end
 end
diff --git a/app/presenters/api/v2/plan_presenter.rb b/app/presenters/api/v2/plan_presenter.rb
index c841844c6c..4e37a45111 100644
--- a/app/presenters/api/v2/plan_presenter.rb
+++ b/app/presenters/api/v2/plan_presenter.rb
@@ -4,9 +4,9 @@ module Api
   module V2
     # Helper class for the API V2 project / DMP
     class PlanPresenter
-      attr_reader :data_contact, :contributors, :costs
+      attr_reader :data_contact, :contributors, :costs, :complete_plan_data
 
-      def initialize(plan:)
+      def initialize(plan:, complete: false)
         @contributors = []
         return unless plan.present?
 
@@ -22,6 +22,8 @@ def initialize(plan:)
         end
 
         @costs = plan_costs(plan: @plan)
+
+        @complete_plan_data = fetch_all_q_and_a if complete
       end
 
       # Extract the ARK or DOI for the DMP OR use its URL if none exists
@@ -55,6 +57,25 @@ def plan_costs(plan:)
             currency_code: 'usd', value: answer.text }
         end
       end
+
+      # Fetch all questions and answers from a plan, regardless of theme
+      def fetch_all_q_and_a
+        answers = @plan.answers
+        return [] unless answers.present?
+
+        answers.filter_map do |answer|
+          q = answer.question
+          next unless q.present?
+
+          {
+            id: q.id,
+            title: "Question #{q.number || q.id}",
+            section: q.section&.title,
+            question: q.text.to_s,
+            answer: answer.text.to_s
+          }
+        end
+      end
     end
   end
 end
diff --git a/app/views/api/v2/plans/_show.json.jbuilder b/app/views/api/v2/plans/_show.json.jbuilder
index 0de52775a3..4b752b15e1 100644
--- a/app/views/api/v2/plans/_show.json.jbuilder
+++ b/app/views/api/v2/plans/_show.json.jbuilder
@@ -4,7 +4,7 @@
 
 json.schema 'https://github.com/RDA-DMP-Common/RDA-DMP-Common-Standard/tree/master/examples/JSON/JSON-schema/1.0'
 
-presenter = Api::V2::PlanPresenter.new(plan: plan)
+presenter = Api::V2::PlanPresenter.new(plan: plan, complete: @complete)
 
 # Note the symbol of the dmproadmap json object
 # nested in extensions which is the container for the json template object, etc.
@@ -68,5 +68,20 @@ unless @minimal
         json.title template.title
       end
     end
+
+    if @complete
+      json.complete_plan do
+        q_and_a = presenter.complete_plan_data
+        next if q_and_a.blank?
+
+        json.array! q_and_a do |item|
+          json.question_id item[:id]
+          json.title item[:title]
+          json.section item[:section]
+          json.question item[:question]
+          json.answer item[:answer]
+        end
+      end
+    end
   end
 end