diff --git a/app/Views/billing/opd_prescription_basic.php b/app/Views/billing/opd_prescription_basic.php
index 5c1fa5d..6b8769f 100644
--- a/app/Views/billing/opd_prescription_basic.php
+++ b/app/Views/billing/opd_prescription_basic.php
@@ -460,6 +460,25 @@
             object-fit: contain;
             background: #f8f9fa;
         }
+        .rx-history-scan-modal-body {
+            max-height: calc(100vh - 140px);
+            min-height: 70vh;
+            overflow: auto;
+            background: #f8f9fa;
+            padding: .75rem;
+        }
+        .rx-history-scan-modal-dialog {
+            width: min(96vw, 1600px);
+            max-width: min(96vw, 1600px);
+        }
+        .rx-history-scan-modal-img {
+            display: block;
+            max-width: 100%;
+            max-height: calc(100vh - 190px);
+            width: auto;
+            height: auto;
+            margin: 0 auto;
+        }
         @media (min-width: 992px) {
             .rx-two-panel {
                 --rx-panel-height: calc(100vh - 170px);
@@ -1636,6 +1655,20 @@
             </div>
         </div>
     </div>
+
+    <div class="modal fade" id="historyScanPreviewModal" tabindex="-1" aria-hidden="true">
+        <div class="modal-dialog rx-history-scan-modal-dialog modal-dialog-centered">
+            <div class="modal-content">
+                <div class="modal-header">
+                    <h5 class="modal-title" id="historyScanPreviewTitle">OPD Scan</h5>
+                    <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
+                </div>
+                <div class="modal-body rx-history-scan-modal-body text-center">
+                    <img src="" alt="OPD history scan" id="historyScanPreviewImage" class="rx-history-scan-modal-img">
+                </div>
+            </div>
+        </div>
+    </div>
 </section>
 
 <script>
@@ -6638,6 +6671,36 @@
         $(this).text($item.hasClass('expanded') ? 'Minimize' : 'Expand');
     });
 
+    $(document).on('click', '.js-history-scan-link', function(e) {
+        var modalEl;
+        var modalInst;
+        var src;
+        var title;
+
+        e.preventDefault();
+
+        src = ($(this).data('scan-src') || $(this).attr('href') || '').toString().trim();
+        if (!src) {
+            return;
+        }
+
+        title = ($(this).data('scan-title') || 'OPD Scan').toString().trim();
+        $('#historyScanPreviewImage').attr('src', src);
+        $('#historyScanPreviewTitle').text(title || 'OPD Scan');
+
+        if (window.bootstrap && window.bootstrap.Modal) {
+            modalEl = document.getElementById('historyScanPreviewModal');
+            modalInst = window.bootstrap.Modal.getOrCreateInstance(modalEl);
+            modalInst.show();
+        } else {
+            window.open(src, '_blank');
+        }
+    });
+
+    $('#historyScanPreviewModal').on('hidden.bs.modal', function() {
+        $('#historyScanPreviewImage').attr('src', '');
+    });
+
     $(document).on('click', '.btn-use-current-scan-report', function() {
         var txt = ($(this).data('report') || '').toString().trim();
         if (!txt) {
diff --git a/app/Views/billing/opd_scan_history_panel.php b/app/Views/billing/opd_scan_history_panel.php
index 31dd3c3..7a3e0a3 100644
--- a/app/Views/billing/opd_scan_history_panel.php
+++ b/app/Views/billing/opd_scan_history_panel.php
@@ -14,7 +14,12 @@
                         <?php if (!empty($scan['is_pdf'])) { ?>
                             <a class="btn btn-outline-secondary btn-sm w-100" target="_blank" href="<?= esc((string) ($scan['path'] ?? '')) ?>">Open PDF</a>
                         <?php } else { ?>
-                            <a target="_blank" href="<?= esc((string) ($scan['path'] ?? '')) ?>">
+                            <a
+                                href="<?= esc((string) ($scan['path'] ?? '')) ?>"
+                                class="js-history-scan-link"
+                                data-scan-src="<?= esc((string) ($scan['path'] ?? '')) ?>"
+                                data-scan-title="<?= esc((string) (($scan['opd_code'] ?? '') !== '' ? $scan['opd_code'] : ('OPD #' . ((int) ($scan['opd_id'] ?? 0)))) . ' ' . ($scan['opd_date'] ?? '')) ?>"
+                            >
                                 <img src="<?= esc((string) ($scan['path'] ?? '')) ?>" loading="lazy" decoding="async" class="rx-history-preview" alt="history scan">
                             </a>
                             <button type="button" class="btn btn-sm btn-outline-secondary mt-1 w-100 btn-history-toggle-image">Expand</button>