diff --git a/js/quiztech-assessment-builder.js b/js/quiztech-assessment-builder.js
index b3c1061..9f1b31e 100644
--- a/js/quiztech-assessment-builder.js
+++ b/js/quiztech-assessment-builder.js
@@ -12,7 +12,7 @@ jQuery(document).ready(function($) {
 
     // --- State ---
     let currentAssessmentQuestions = []; // Array to hold IDs of questions in the right pane
-    let currentAssessmentId = null; // Store the ID if editing an existing assessment (TODO: Load this if editing)
+    let currentAssessmentId = null; // Store the ID if editing an existing assessment
 
     // --- Functions ---
 
@@ -202,6 +202,63 @@ jQuery(document).ready(function($) {
     }
 
 
+    /**
+     * Fetches data for an existing assessment and populates the builder.
+     * @param {number} assessmentId The ID of the assessment to load.
+     */
+    function loadExistingAssessment(assessmentId) {
+        console.log('Loading assessment:', assessmentId);
+        // Show some loading indicator maybe?
+        $saveStatus.text('Loading assessment data...').removeClass('success error'); // TODO: Localize
+
+        $.post(quiztechBuilderData.ajax_url, {
+            action: 'quiztech_fetch_assessment_data',
+            // nonce: quiztechBuilderData.fetch_nonce, // TODO: Implement nonce verification in PHP
+            assessment_id: assessmentId
+        })
+        .done(function(response) {
+            if (response.success && response.data) {
+                currentAssessmentId = assessmentId; // Set the ID in state
+                $assessmentTitleInput.val(response.data.title || '');
+
+                // Clear placeholder and render questions
+                $currentList.empty();
+                if (response.data.questions && response.data.questions.length > 0) {
+                    response.data.questions.forEach(function(q) {
+                        const itemHtml = `
+                            <div class="selected-question-item" data-question-id="${q.id}" data-cost="${q.cost}">
+                                <span>
+                                    <strong>${q.title || 'Untitled'}</strong> (Type: ${q.type || 'N/A'}) [Cost: ${q.cost || 0}] <!-- TODO: Localize -->
+                                </span>
+                                <button class="remove-question-from-assessment" data-question-id="${q.id}">Remove</button> <!-- TODO: Localize -->
+                            </div>
+                        `;
+                        $currentList.append(itemHtml);
+                    });
+                } else {
+                    // Add placeholder if no questions were returned
+                    $currentList.html('<p>' + 'No questions added yet.' + '</p>'); // TODO: Localize
+                }
+
+                // Update state and UI based on loaded data
+                updateStateFromDOM();
+                updateTotalCost();
+                updateLibraryButtons(); // Disable 'Add' buttons for loaded questions
+                $saveStatus.text('Assessment loaded.').addClass('success'); // TODO: Localize
+                setTimeout(() => $saveStatus.empty().removeClass('success'), 3000); // Clear status after a delay
+
+            } else {
+                $saveStatus.text(response.data.message || 'Error loading assessment.').addClass('error'); // TODO: Localize
+                // Maybe redirect or show a more prominent error?
+            }
+        })
+        .fail(function() {
+            $saveStatus.text('Error loading assessment.').addClass('error'); // TODO: Localize
+        });
+    }
+
+
+
     // --- Event Handlers ---
 
     // Add question from library to current assessment (Handles manual click - less relevant with drag/drop but keep for now)
@@ -302,6 +359,15 @@ jQuery(document).ready(function($) {
         }
     }).disableSelection(); // Prevent text selection while dragging
 
+
+    // --- Check for Edit Mode on Load ---
+    const urlParams = new URLSearchParams(window.location.search);
+    const editAssessmentId = urlParams.get('assessment_id');
+
+    if (editAssessmentId && !isNaN(parseInt(editAssessmentId))) {
+        loadExistingAssessment(parseInt(editAssessmentId));
+    }
+
     // --- Initial Load ---
     fetchLibraryQuestions(); // Load initial questions into the library (will also init draggable)
     // renderCurrentAssessment(); // Don't render initially, sortable handles it