diff --git a/components/lib/panel/Panel.d.ts b/components/lib/panel/Panel.d.ts
index 256cbfa16..e7c7fecbb 100755
--- a/components/lib/panel/Panel.d.ts
+++ b/components/lib/panel/Panel.d.ts
@@ -10,6 +10,8 @@
 import { ButtonHTMLAttributes, VNode } from 'vue';
 import { ClassComponent, GlobalComponentConstructor } from '../ts-helpers';
 
+export declare type PanelPassThroughOptionType = PanelPassThroughAttributes | ((options: { props: PanelProps; state: PanelState }) => PanelPassThroughAttributes) | null | undefined;
+
 /**
  * Custom toggle event.
  * @see {@link PanelEmits.toggle}
@@ -25,6 +27,62 @@ export interface PanelToggleEvent {
     value: boolean;
 }
 
+/**
+ * Custom passthrough(pt) options.
+ * @see {@link PanelProps.pt}
+ */
+export interface PanelPassThroughOptions {
+    /**
+     * Uses to pass attributes to the root's DOM element.
+     */
+    root?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the header's DOM element.
+     */
+    header?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the title's DOM element.
+     */
+    title?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the title's DOM element.
+     */
+    icons?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the toggler's DOM element.
+     */
+    toggler?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the headericon's DOM element.
+     */
+    headericon?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the toggleablecontent's DOM element.
+     */
+    toggleablecontent?: PanelPassThroughOptionType;
+    /**
+     * Uses to pass attributes to the content's DOM element.
+     */
+    content?: PanelPassThroughOptionType;
+}
+
+/**
+ * Custom passthrough attributes for each DOM elements
+ */
+export interface PanelPassThroughAttributes {
+    [key: string]: any;
+}
+
+/**
+ * Defines current inline states in Panel component.
+ */
+export interface PanelState {
+    /**
+     * Current collapsed state as a boolean
+     */
+    d_collapsed: boolean;
+}
+
 /**
  * Defines valid properties in Panel component.
  */
@@ -47,6 +105,11 @@ export interface PanelProps {
      * Uses to pass the custom value to read for the button inside the component.
      */
     toggleButtonProps?: ButtonHTMLAttributes | undefined;
+    /**
+     * Uses to pass attributes to DOM elements inside the component.
+     * @type {PanelPassThroughOptions}
+     */
+    pt?: PanelPassThroughOptions;
 }
 
 /**
@@ -65,6 +128,16 @@ export interface PanelSlots {
      * Custom icons template.
      */
     icons(): VNode[];
+    /**
+     * Custom header icon template of panel.
+     * @param {Object} scope - header icon slot's params.
+     */
+    headericon(scope: {
+        /**
+         * Collapsed state as a boolean
+         */
+        collapsed: boolean;
+    }): VNode[];
 }
 
 /**
diff --git a/components/lib/panel/Panel.vue b/components/lib/panel/Panel.vue
index b906d729a..364deae4e 100755
--- a/components/lib/panel/Panel.vue
+++ b/components/lib/panel/Panel.vue
@@ -12,7 +12,7 @@
                     v-ripple
                     type="button"
                     role="button"
-                    class="p-panel-toggler p-link"
+                    class="p-panel-header-icon p-panel-toggler p-link"
                     :aria-label="buttonAriaLabel"
                     :aria-controls="ariaId + '_content'"
                     :aria-expanded="!d_collapsed"
@@ -20,7 +20,9 @@
                     @keydown="onKeyDown"
                     v-bind="{ ...toggleButtonProps, ...ptm('toggler') }"
                 >
-                    <span :class="['p-panel-header-icon', { 'pi pi-minus': !d_collapsed, 'pi pi-plus': d_collapsed }]" v-bind="ptm('headericon')"></span>
+                    <slot name="headericon" :collapsed="d_collapsed">
+                        <span :class="{ 'pi pi-minus': !d_collapsed, 'pi pi-plus': d_collapsed }" v-bind="ptm('headericon')"></span>
+                    </slot>
                 </button>
             </div>
         </div>
diff --git a/doc/common/apidoc/index.json b/doc/common/apidoc/index.json
index a86746fcb..811ad63fb 100644
--- a/doc/common/apidoc/index.json
+++ b/doc/common/apidoc/index.json
@@ -17407,6 +17407,90 @@
                         }
                     ]
                 },
+                "PanelPassThroughAttributes": {
+                    "description": "Custom passthrough attributes for each DOM elements",
+                    "relatedProp": "",
+                    "props": [
+                        {
+                            "name": "[key: string]",
+                            "optional": false,
+                            "readonly": false,
+                            "type": "any"
+                        }
+                    ],
+                    "methods": []
+                },
+                "PanelPassThroughOptions": {
+                    "description": "Custom passthrough(pt) options.",
+                    "relatedProp": "PanelProps.pt",
+                    "props": [
+                        {
+                            "name": "content",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the content's DOM element."
+                        },
+                        {
+                            "name": "header",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the header's DOM element."
+                        },
+                        {
+                            "name": "headericon",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the headericon's DOM element."
+                        },
+                        {
+                            "name": "icons",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the title's DOM element."
+                        },
+                        {
+                            "name": "root",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the root's DOM element."
+                        },
+                        {
+                            "name": "title",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the title's DOM element."
+                        },
+                        {
+                            "name": "toggleablecontent",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the toggleablecontent's DOM element."
+                        },
+                        {
+                            "name": "toggler",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptionType",
+                            "default": "",
+                            "description": "Uses to pass attributes to the toggler's DOM element."
+                        }
+                    ],
+                    "methods": []
+                },
                 "PanelProps": {
                     "description": "Defines valid properties in Panel component.",
                     "relatedProp": "",
@@ -17427,6 +17511,14 @@
                             "default": "",
                             "description": "Header text of the panel."
                         },
+                        {
+                            "name": "pt",
+                            "optional": true,
+                            "readonly": false,
+                            "type": "PanelPassThroughOptions",
+                            "default": "",
+                            "description": "Uses to pass attributes to DOM elements inside the component."
+                        },
                         {
                             "name": "toggleButtonProps",
                             "optional": true,
@@ -17463,6 +17555,19 @@
                             "returnType": "VNode<RendererNode, RendererElement, Object>[]",
                             "description": "Custom header template."
                         },
+                        {
+                            "name": "headericon",
+                            "parameters": [
+                                {
+                                    "name": "scope",
+                                    "optional": false,
+                                    "type": "{\n  \t <b>collapsed</b>: boolean, // Collapsed state as a boolean\n  }",
+                                    "description": "header icon slot's params."
+                                }
+                            ],
+                            "returnType": "VNode<RendererNode, RendererElement, Object>[]",
+                            "description": "Custom header icon template of panel."
+                        },
                         {
                             "name": "icons",
                             "parameters": [],
@@ -17471,6 +17576,21 @@
                         }
                     ]
                 },
+                "PanelState": {
+                    "description": "Defines current inline states in Panel component.",
+                    "relatedProp": "",
+                    "props": [
+                        {
+                            "name": "d_collapsed",
+                            "optional": false,
+                            "readonly": false,
+                            "type": "boolean",
+                            "default": "",
+                            "description": "Current collapsed state as a boolean"
+                        }
+                    ],
+                    "methods": []
+                },
                 "PanelToggleEvent": {
                     "description": "Custom toggle event.",
                     "relatedProp": "PanelEmits.toggle",
@@ -17495,6 +17615,14 @@
                     "methods": []
                 }
             }
+        },
+        "types": {
+            "description": "Defines the custom types used by the module.",
+            "values": {
+                "PanelPassThroughOptionType": {
+                    "values": "PanelPassThroughAttributes | Function | null | undefined"
+                }
+            }
         }
     },
     "panelmenu": {