diff --git a/app/components/form/multiple_select_component.html.erb b/app/components/form/multiple_select_component.html.erb
index 58bb6f3098..79f8efaaa2 100644
--- a/app/components/form/multiple_select_component.html.erb
+++ b/app/components/form/multiple_select_component.html.erb
@@ -3,6 +3,7 @@
      data-multiple-select-options-value="<%= @options %>"
      data-multiple-select-selected-items-value="<%= @selected_items %>"
      data-multiple-select-placeholder-term-value="<%= @placeholder_term %>"
+     data-multiple-select-show-all-option-value="<%= @show_all_option %>"
      data-multiple-select-with-options-value="true">
 
   <template data-multiple-select-target="option">
@@ -18,6 +19,18 @@
     <div class="badge rounded-pill bg-primary active px-3">DATA_LABEL</div>
   </template>
 
+  <% if @show_all_option %>
+    <template data-multiple-select-target="hiddenItem">
+      <div class="d-none"></div>
+    </template>
+
+    <template data-multiple-select-target="showAllOption">
+      <div class="fug d-flex align-items-baseline show-all-options" data-multiple-select-target="showAllOption" data-action="multiple-select#toggleSelectAll">
+        <span class='mr-5'>DATA_LABEL</span>
+      </div>
+    </template>
+  <% end %>
+  
   <%= @form.select @name, {}, { multiple: true } , {
     data: { "multiple-select-target": "select",  } , class: "form-control-lg form-select form-select-lg input-group-lg"
   } %>
diff --git a/app/components/form/multiple_select_component.rb b/app/components/form/multiple_select_component.rb
index 4df7c864bc..c2f0725c1d 100644
--- a/app/components/form/multiple_select_component.rb
+++ b/app/components/form/multiple_select_component.rb
@@ -1,12 +1,13 @@
 # frozen_string_literal: true
 
 class Form::MultipleSelectComponent < ViewComponent::Base
-  def initialize(form:, name:, options:, selected_items:, render_option_subtext: false, placeholder_term: nil)
+  def initialize(form:, name:, options:, selected_items:, render_option_subtext: false, placeholder_term: nil, show_all_option: false)
     @form = form
     @name = name
     @options = options.to_json
     @selected_items = selected_items
     @render_option_subtext = render_option_subtext
     @placeholder_term = placeholder_term
+    @show_all_option = show_all_option
   end
 end
diff --git a/app/javascript/controllers/multiple_select_controller.js b/app/javascript/controllers/multiple_select_controller.js
index 1ebd2dd6ec..574d4cf638 100644
--- a/app/javascript/controllers/multiple_select_controller.js
+++ b/app/javascript/controllers/multiple_select_controller.js
@@ -2,7 +2,7 @@ import { Controller } from '@hotwired/stimulus'
 import TomSelect from 'tom-select'
 
 export default class extends Controller {
-  static targets = ['select', 'option', 'item']
+  static targets = ['select', 'option', 'item', 'hiddenItem', 'showAllOption'] // add 'selectAllBtn' if going with button
   static values = {
     options: Array,
     selectedItems: Array,
@@ -10,7 +10,8 @@ export default class extends Controller {
     placeholderTerm: {
       type: String,
       default: 'contact(s)'
-    }
+    },
+    showAllOption: Boolean,
   }
 
   connect () {
@@ -37,11 +38,52 @@ export default class extends Controller {
     const itemTemplate = this.itemTarget.innerHTML
     const placeholder = `Select or search ${this.placeholderTermValue}`
 
+    const showAllOptionCheck = this.showAllOptionValue
+    const hiddenItemTemplate = showAllOptionCheck && this.hiddenItemTarget && this.hiddenItemTarget.innerHTML
+    const showAllOptionTemplate = showAllOptionCheck && this.showAllOptionTarget && this.showAllOptionTarget.innerHTML
+    
+    // orderedOptionVals is of type (" " | number)[] - the " " could appear
+    // because using it as the value for the select/unselect all option
+    let orderedOptionVals = this.optionsValue.map(opt => opt.value)
+    if (showAllOptionCheck) {
+      // using " " as value instead of "" bc tom-select doesn't init the "" in the item list
+      orderedOptionVals = [" "].concat(orderedOptionVals)
+    }
+
+    // used to determine initial items selected by tom-select
+    const initItems = this.selectedItemsValue?.length ? this.selectedItemsValue : orderedOptionVals
+
+    const dropdownOptions = showAllOptionCheck ? 
+      [{ text: "Select/Unseselect all", subtext: "", value: " ", group: ""}].concat(this.optionsValue) 
+        : this.optionsValue
+    
+    // const selectAllBtn = this.selectAllBtnTarget
+    // assign TomSelect instance to this.selectEl if going with button implementation
+
     /* eslint-disable no-new */
     new TomSelect(this.selectTarget, {
-      onItemAdd: function () {
+      onItemRemove: function(value, data) {
+        // for the select/unselect all button - add in short circuit in case showAllBtn doesn't exist
+        // if (this.items.length < orderedOptionVals.length) {
+        //   selectAllBtn.innerText = 'Select all'
+        // }
+
+        if (value === " ") {
+          this.clear()
+        }
+      },
+      onItemAdd: function (value) {
         this.setTextboxValue('')
         this.refreshOptions()
+
+        // for the select/unselect all button - add in short circuit in case showAllBtn doesn't exist
+        // if (this.items.length < orderedOptionVals.length) {
+        //   selectAllBtn.innerText = 'Select all'
+        // }
+
+        if (value === " ") {
+          this.addItems(orderedOptionVals);
+        }
       },
       plugins: {
         remove_button: {
@@ -54,21 +96,42 @@ export default class extends Controller {
           uncheckedClassNames: ['form-check-input']
         }
       },
-      options: this.optionsValue,
-      items: this.selectedItemsValue,
+      options: dropdownOptions,
+      items: initItems,
       placeholder,
       hidePlaceholder: true,
       searchField: ['text', 'group'],
       render: {
         option: function (data, escape) {
-          let html = optionTemplate.replace(/DATA_LABEL/g, escape(data.text))
-          html = html.replace(/DATA_SUB_TEXT/g, escape(data.subtext))
+          let html
+
+          if (showAllOptionCheck && data && data.value === " ") {
+            html = showAllOptionTemplate.replace(/DATA_LABEL/g, escape(data.text))
+          } else {
+            html = optionTemplate.replace(/DATA_LABEL/g, escape(data.text))
+            html = html.replace(/DATA_SUB_TEXT/g, escape(data.subtext))
+          }
           return html
         },
         item: function (data, escape) {
-          return itemTemplate.replace(/DATA_LABEL/g, escape(data.text))
+          return showAllOptionCheck && data.value === " " ? hiddenItemTemplate : itemTemplate.replace(/DATA_LABEL/g, escape(data.text))
         }
       }
     })
   }
+
+  // action for the select/unselect all button - add in short circuit in case showAllBtn or selectEl doesn't exist
+  // toggleSelectAll() {
+  //   if (!this.selectEl || !this.selectAllBtnTarget) return
+
+  //   const checkedStatus = this.selectEl.items.length === Object.keys(this.selectEl.options).length ? "all" : "not-all"
+    
+  //   if (checkedStatus === "all") {
+  //     this.selectEl.clear()
+  //     this.selectAllBtnTarget.textContent = "Select all"
+  //   } else {
+  //     this.selectEl.addItems(this.optionsValue.map(opt => opt.value))
+  //     this.selectAllBtnTarget.textContent = "Unselect all"
+  //   }
+  // }
 }
diff --git a/app/views/case_contacts/form/_contact_types.html.erb b/app/views/case_contacts/form/_contact_types.html.erb
index 1f91e5f1d1..517d71b65b 100644
--- a/app/views/case_contacts/form/_contact_types.html.erb
+++ b/app/views/case_contacts/form/_contact_types.html.erb
@@ -5,6 +5,7 @@
     name: :contact_type_ids,
     options: options.decorate.map { |ct| ct.hash_for_multi_select_with_cases(casa_cases&.pluck(:id)) },
     selected_items: selected_items,
-    render_option_subtext: true
+    render_option_subtext: true,
+    show_all_option: true,
   )) %>
 </div>