diff --git a/app/assets/stylesheets/base/helpers.scss b/app/assets/stylesheets/base/helpers.scss
index f3a664adb..abc7db77e 100644
--- a/app/assets/stylesheets/base/helpers.scss
+++ b/app/assets/stylesheets/base/helpers.scss
@@ -36,15 +36,6 @@
   border-top: var(--su-7) solid var(--accent-brand);
 }
 
-.screen-reader-only {
-  position: absolute;
-  left: -10000px;
-  top: auto;
-  width: 1px;
-  height: 1px;
-  overflow: hidden;
-}
-
 @media print {
   .print-hidden {
     display: none;
diff --git a/app/assets/stylesheets/components/autocomplete.scss b/app/assets/stylesheets/components/autocomplete.scss
index 933a4afe3..e3d3323c1 100644
--- a/app/assets/stylesheets/components/autocomplete.scss
+++ b/app/assets/stylesheets/components/autocomplete.scss
@@ -2,9 +2,8 @@
 
 .crayons-autocomplete {
   &__popover {
-    max-width: 300px;
+    min-width: 300px;
     padding: var(--su-1);
-    z-index: var(--z-elevate);
 
     &[data-reach-popover] {
       @include generate-box(
diff --git a/app/javascript/crayons/MentionAutocomplete/MentionAutocomplete.jsx b/app/javascript/crayons/MentionAutocomplete/MentionAutocomplete.jsx
new file mode 100644
index 000000000..3c541c3e8
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/MentionAutocomplete.jsx
@@ -0,0 +1,141 @@
+import { h, render } from 'preact';
+import { useState, useEffect, useCallback } from 'preact/hooks';
+import { getCursorXY } from '@utilities/textAreaUtils';
+import { useMediaQuery, BREAKPOINTS } from '@components/useMediaQuery';
+
+/**
+ * A component which listens for an '@' keypress, and encompasses the MentionAutocomplete functionality.
+ * When an autocomplete suggestion is selected, it is inserted into the textarea.
+ *
+ * @param {object} props
+ * @param {object} props.textAreaRef A reference to the text area where an '@' mention can take place
+ * @param {function} props.fetchSuggestions The callback to search for suggestions
+ *
+ * @example
+ * <Fragment>
+ *    <textarea
+ *      ref={textAreaRef}
+ *      aria-label="test text area"/>
+ *    <MentionAutocomplete
+ *      textAreaRef={textAreaRef}
+ *      fetchSuggestions={fetchUsers}
+ *    />
+ * </Fragment>
+ */
+export const MentionAutocomplete = ({ textAreaRef, fetchSuggestions }) => {
+  const [isAutocompleteActive, setIsAutocompleteActive] = useState(false);
+  const [cursorPlacementData, setCursorPlacementData] = useState({});
+
+  const isSmallScreen = useMediaQuery(`(max-width: ${BREAKPOINTS.Small}px)`);
+
+  const handleSearchTermChange = useCallback(
+    (searchTerm) => {
+      const { textBefore, textAfter } = cursorPlacementData;
+
+      const newValue = `${textBefore}${searchTerm}${textAfter}`;
+      textAreaRef.current.value = newValue;
+    },
+    [cursorPlacementData, textAreaRef],
+  );
+
+  const handleSelection = useCallback(
+    (selection) => {
+      const { textBefore, textAfter } = cursorPlacementData;
+      const newValueUntilEndOfSearch = `${textBefore}${selection}`;
+      textAreaRef.current.value = `${newValueUntilEndOfSearch}${textAfter}`;
+
+      const nextCursorPosition = newValueUntilEndOfSearch.length;
+      setIsAutocompleteActive(false);
+      textAreaRef.current.focus();
+      textAreaRef.current.setSelectionRange(
+        nextCursorPosition,
+        nextCursorPosition,
+      );
+    },
+    [cursorPlacementData, textAreaRef],
+  );
+
+  useEffect(() => {
+    const keyEventListener = ({ key }) => {
+      if (key === '@') {
+        if (!shouldKeyPressTriggerSearch(textAreaRef.current)) {
+          return;
+        }
+
+        const textAreaX = textAreaRef.current.offsetLeft;
+        const cursorCoords = getCursorXY(
+          textAreaRef.current,
+          textAreaRef.current.selectionStart,
+        );
+
+        const coords = {
+          y: cursorCoords.y,
+          x: isSmallScreen ? textAreaX : cursorCoords.x,
+        };
+
+        setCursorPlacementData({
+          ...coords,
+          textBefore: textAreaRef.current.value.substring(
+            0,
+            textAreaRef.current.selectionStart,
+          ),
+          textAfter: textAreaRef.current.value.substring(
+            textAreaRef.current.selectionStart,
+          ),
+        });
+        setIsAutocompleteActive(true);
+      }
+    };
+
+    const textArea = textAreaRef.current;
+
+    if (textArea) {
+      textArea.addEventListener('keydown', keyEventListener);
+      return () => textArea.removeEventListener('keydown', keyEventListener);
+    }
+  }, [textAreaRef, isSmallScreen]);
+
+  useEffect(() => {
+    const container = document.getElementById('mention-autocomplete-container');
+    if (!container) {
+      return;
+    }
+    if (isAutocompleteActive) {
+      import('./MentionAutocompleteCombobox').then(
+        ({ MentionAutocompleteCombobox }) => {
+          render(
+            <MentionAutocompleteCombobox
+              onSelect={handleSelection}
+              fetchSuggestions={fetchSuggestions}
+              placementCoords={cursorPlacementData}
+              onSearchTermChange={handleSearchTermChange}
+            />,
+            container,
+          );
+        },
+      );
+    } else {
+      render(null, container);
+    }
+  }, [
+    cursorPlacementData,
+    fetchSuggestions,
+    handleSearchTermChange,
+    handleSelection,
+    isAutocompleteActive,
+  ]);
+
+  return <span id="mention-autocomplete-container" />;
+};
+
+const VALID_PREVIOUS_CHAR_REGEX = new RegExp(/[^A-Za-z0-9]/);
+const shouldKeyPressTriggerSearch = (textArea) => {
+  const { selectionStart, value: valueBeforeKeystroke } = textArea;
+
+  const previousCharacter = valueBeforeKeystroke.charAt(selectionStart - 1);
+
+  return (
+    previousCharacter === '' ||
+    VALID_PREVIOUS_CHAR_REGEX.test(previousCharacter)
+  );
+};
diff --git a/app/javascript/crayons/MentionAutocomplete/MentionAutocompleteCombobox.jsx b/app/javascript/crayons/MentionAutocomplete/MentionAutocompleteCombobox.jsx
new file mode 100644
index 000000000..1319abc7c
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/MentionAutocompleteCombobox.jsx
@@ -0,0 +1,177 @@
+import { h, Fragment } from 'preact';
+import { useState, useEffect, useRef, useLayoutEffect } from 'preact/hooks';
+import PropTypes from 'prop-types';
+import {
+  Combobox,
+  ComboboxInput,
+  ComboboxPopover,
+  ComboboxList,
+  ComboboxOption,
+} from '@reach/combobox';
+import '@reach/combobox/styles.css';
+
+const UserListItemContent = ({ user }) => {
+  return (
+    <Fragment>
+      <span className="crayons-avatar crayons-avatar--l mr-2 shrink-0">
+        <img
+          src={user.profile_image_90}
+          alt=""
+          className="crayons-avatar__image "
+        />
+      </span>
+
+      <div>
+        <p className="crayons-autocomplete__name">{user.name}</p>
+        <p className="crayons-autocomplete__username">{`@${user.username}`}</p>
+      </div>
+    </Fragment>
+  );
+};
+
+/**
+ * A component for dynamically searching for users and displaying results in a dropdown.
+ * This component should be mounted when a user has started typing a mention with the '@' symbol, and will be positioned at the given coordinates.
+ *
+ * @param {object} props
+ * @param {string} props.startText The initial search term to use
+ * @param {function} props.onSelect Callback function for using the selected user
+ * @param {function} props.fetchSuggestions The async call to use for the search
+ * @param {object} props.placementCoords The x/y coordinates for placement of the popover
+ * @param {function} props.onSearchTermChange A callback for each time the searchTerm changes
+ *
+ * @example
+ * <MentionAutocompleteCombobox
+ *    startText="name"
+ *    onSelect={handleUserMentionSelection}
+ *    fetchSuggestions={fetchUsersByUsername}
+ *    placementCoords={{x: 22, y: 0}}
+ *    onSearchTermChange={updateSearchTermText}
+ * />
+ */
+export const MentionAutocompleteCombobox = ({
+  onSelect,
+  fetchSuggestions,
+  placementCoords,
+  onSearchTermChange,
+}) => {
+  const [searchTerm, setSearchTerm] = useState('@');
+  const [cachedSearches, setCachedSearches] = useState({});
+  const [users, setUsers] = useState([]);
+
+  const inputRef = useRef(null);
+
+  useEffect(() => {
+    if (searchTerm.length >= 3) {
+      // Remove the '@' symbol for search
+      const trimmedSearchTerm = searchTerm.substring(1);
+
+      if (cachedSearches[trimmedSearchTerm]) {
+        setUsers(cachedSearches[trimmedSearchTerm]);
+        return;
+      }
+
+      fetchSuggestions(trimmedSearchTerm).then((fetchedUsers) => {
+        setCachedSearches({
+          ...cachedSearches,
+          [trimmedSearchTerm]: fetchedUsers,
+        });
+        setUsers(fetchedUsers);
+      });
+    }
+  }, [searchTerm, fetchSuggestions, cachedSearches]);
+
+  useEffect(() => {
+    inputRef.current.focus();
+  }, [inputRef]);
+
+  useLayoutEffect(() => {
+    const popover = document.getElementById('mention-autocomplete-popover');
+    if (!popover) {
+      return;
+    }
+
+    const closeOnClickOutsideListener = (event) => {
+      if (!popover.contains(event.target)) {
+        // User clicked outside, exit with current search term
+        onSelect(searchTerm);
+      }
+    };
+
+    document.addEventListener('click', closeOnClickOutsideListener);
+
+    return () =>
+      document.removeEventListener('click', closeOnClickOutsideListener);
+  }, [searchTerm, onSelect]);
+
+  const handleSearchTermChange = (event) => {
+    const {
+      target: { value },
+    } = event;
+
+    if (value.charAt(value.length - 1) === ' ' || value === '') {
+      // User has spaced away from a complete word or deleted everything - finish the autocomplete
+      onSelect(value);
+      return;
+    }
+    setSearchTerm(value);
+    onSearchTermChange(value);
+  };
+
+  return (
+    <Combobox
+      aria-label="mention user"
+      onSelect={(item) => onSelect(`@${item}`)}
+      className="crayons-autocomplete"
+    >
+      <ComboboxInput
+        style={{
+          opacity: 0.000001,
+        }}
+        ref={inputRef}
+        onChange={handleSearchTermChange}
+        value={searchTerm}
+        selectOnClick
+        autocomplete={false}
+      />
+      <ComboboxPopover
+        className="crayons-autocomplete__popover"
+        id="mention-autocomplete-popover"
+        style={{
+          position: 'absolute',
+          top: `calc(${placementCoords.y}px + 1.5rem)`,
+          left: `${placementCoords.x}px`,
+        }}
+      >
+        {users.length > 0 ? (
+          <ComboboxList>
+            {users.map((user) => (
+              <ComboboxOption
+                value={user.username}
+                className="crayons-autocomplete__option flex items-center"
+              >
+                <UserListItemContent user={user} />
+              </ComboboxOption>
+            ))}
+          </ComboboxList>
+        ) : (
+          <span className="crayons-autocomplete__empty">
+            {searchTerm.length >= 2
+              ? 'No results found'
+              : 'Type to search for a user'}
+          </span>
+        )}
+      </ComboboxPopover>
+    </Combobox>
+  );
+};
+
+MentionAutocompleteCombobox.propTypes = {
+  onSelect: PropTypes.func.isRequired,
+  fetchSuggestions: PropTypes.func.isRequired,
+  placementCoords: PropTypes.shape({
+    x: PropTypes.number,
+    y: PropTypes.number,
+  }).isRequired,
+  onSearchTermChange: PropTypes.func.isRequired,
+};
diff --git a/app/javascript/crayons/MentionAutocomplete/__stories__/MentionAutocomplete.stories.jsx b/app/javascript/crayons/MentionAutocomplete/__stories__/MentionAutocomplete.stories.jsx
new file mode 100644
index 000000000..e2034fb07
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/__stories__/MentionAutocomplete.stories.jsx
@@ -0,0 +1,75 @@
+import { h, createRef, Fragment } from 'preact';
+import notes from './mention-autocomplete.md';
+import { MentionAutocomplete } from '@crayons/MentionAutocomplete';
+
+export default {
+  title: 'Components/MentionAutocomplete',
+  parameters: { notes },
+};
+
+function fetchUsers(searchTerm) {
+  const exampleApiResult = {
+    result: [
+      {
+        username: 'user_one',
+        name: 'User One First Name Last Name',
+        profile_image_90: '/images/apple-icon.png',
+      },
+      {
+        username: 'user_two',
+        name: 'User Two',
+        profile_image_90: '/images/apple-icon.png',
+      },
+      {
+        username: 'user_three',
+        name: 'User Three',
+        profile_image_90: '/images/apple-icon.png',
+      },
+      {
+        username: 'user_four',
+        name: 'User Four',
+        profile_image_90: '/images/apple-icon.png',
+      },
+      {
+        username: 'user_five',
+        name: 'User Five',
+        profile_image_90: '/images/apple-icon.png',
+      },
+      {
+        username: 'user_six',
+        name: 'User Six First Name Last Name Longer',
+        profile_image_90: '/images/apple-icon.png',
+      },
+    ],
+  };
+
+  return Promise.resolve(
+    exampleApiResult.result.filter((user) =>
+      user.username.includes(searchTerm),
+    ),
+  );
+}
+
+export const Default = () => {
+  const textAreaRef = createRef(null);
+  return (
+    <Fragment>
+      <label style={{ display: 'flex', flexDirection: 'column' }}>
+        Enter text and type '@us' to start triggering search results
+        <textarea
+          ref={textAreaRef}
+          style={{ width: '500px', maxWidth: '100%', minHeight: '200px' }}
+        />
+      </label>
+
+      <MentionAutocomplete
+        textAreaRef={textAreaRef}
+        fetchSuggestions={fetchUsers}
+      />
+    </Fragment>
+  );
+};
+
+Default.story = {
+  name: 'default',
+};
diff --git a/app/javascript/crayons/MentionAutocomplete/__stories__/mention-autocomplete.md b/app/javascript/crayons/MentionAutocomplete/__stories__/mention-autocomplete.md
new file mode 100644
index 000000000..76e7c8c57
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/__stories__/mention-autocomplete.md
@@ -0,0 +1,14 @@
+## Mention autocomplete
+
+The mention autocomplete component uses the [Reach UI Combobox](https://reach.tech/combobox/) under the hood. It can be used for searching for users by username by passing in a reference to the relevant text area.
+
+The autocomplete will begin fetching suggestions once a user has type '@' plus at least two characters. A user's selection is confirmed when they either:
+
+- Click on a search option
+- Hit enter on a search option
+- Click away from the dropdown
+- Enter space to move away from the autocomplete
+
+### Mention autocomplete accessibility
+
+The component works by switching focus to an invisible combobox input once the user types @. Focus is sent back to the original textarea when selection is completed. The underlying [Reach UI Combobox](https://reach.tech/combobox/) behavior conforms to the [WAI_ARIA guidelines on comboboxes](https://www.w3.org/TR/wai-aria-practices-1.2/#combobox).
diff --git a/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocomplete.test.jsx b/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocomplete.test.jsx
new file mode 100644
index 000000000..9052d3569
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocomplete.test.jsx
@@ -0,0 +1,38 @@
+import { h, Fragment, createRef } from 'preact';
+import { render } from '@testing-library/preact';
+import '@testing-library/jest-dom';
+import { axe } from 'jest-axe';
+import { MentionAutocomplete } from '../MentionAutocomplete';
+
+describe('<MentionAutocomplete />', () => {
+  const testTextAreaRef = createRef(null);
+  const testTextArea = (
+    <textarea ref={testTextAreaRef} aria-label="test text area" />
+  );
+
+  const mockFetchSuggestions = jest.fn();
+
+  it('should have no a11y violations when rendered', async () => {
+    global.window.matchMedia = jest.fn((query) => {
+      return {
+        matches: false,
+        media: query,
+        addListener: jest.fn(),
+        removeListener: jest.fn(),
+      };
+    });
+
+    const { container } = render(
+      <Fragment>
+        {testTextArea}
+        <MentionAutocomplete
+          textAreaRef={testTextAreaRef}
+          fetchSuggestions={mockFetchSuggestions}
+        />
+      </Fragment>,
+    );
+
+    const results = await axe(container);
+    expect(results).toHaveNoViolations();
+  });
+});
diff --git a/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocompleteCombobox.test.jsx b/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocompleteCombobox.test.jsx
new file mode 100644
index 000000000..734743a3a
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/__tests__/MentionAutocompleteCombobox.test.jsx
@@ -0,0 +1,110 @@
+import { h } from 'preact';
+import { render, waitFor } from '@testing-library/preact';
+import userEvent from '@testing-library/user-event';
+import '@testing-library/jest-dom';
+import { axe } from 'jest-axe';
+import { MentionAutocompleteCombobox } from '../MentionAutocompleteCombobox';
+
+describe('<MentionAutocomplete />', () => {
+  const mockCoords = {
+    x: 0,
+    y: 0,
+  };
+
+  const mockOnSelect = jest.fn();
+  const mockOnSearchtermChange = jest.fn();
+
+  it('should have no a11y violations when rendered', async () => {
+    const { container } = render(
+      <MentionAutocompleteCombobox
+        onSelect={mockOnSelect}
+        onSearchTermChange={mockOnSearchtermChange}
+        fetchSuggestions={() => Promise.resolve([])}
+        placementCoords={mockCoords}
+      />,
+    );
+
+    const results = await axe(container);
+
+    expect(results).toHaveNoViolations();
+  });
+
+  it('should render', () => {
+    const { container } = render(
+      <MentionAutocompleteCombobox
+        onSelect={mockOnSelect}
+        onSearchTermChange={mockOnSearchtermChange}
+        fetchSuggestions={() => Promise.resolve([])}
+        placementCoords={mockCoords}
+      />,
+    );
+
+    expect(container.innerHTML).toMatchSnapshot();
+  });
+
+  it('should not fetch suggestions with less than three characters', async () => {
+    const mockFetchSuggestions = jest.fn();
+
+    const { getByLabelText } = render(
+      <MentionAutocompleteCombobox
+        startText="us"
+        onSelect={mockOnSelect}
+        onSearchTermChange={mockOnSearchtermChange}
+        fetchSuggestions={mockFetchSuggestions}
+        placementCoords={mockCoords}
+      />,
+    );
+
+    expect(mockFetchSuggestions.mock.calls.length).toBe(0);
+    const input = getByLabelText('mention user');
+    userEvent.type(input, 'us');
+    expect(mockFetchSuggestions.mock.calls.length).toBe(0);
+  });
+
+  it('should fetch and display suggestions when search text changes to more than 3 characters', async () => {
+    const mockMatchingUser = {
+      username: 'user_1',
+      name: 'User One',
+      profile_image_90: 'example.png',
+    };
+    const mockFetchSuggestions = jest.fn(() =>
+      Promise.resolve([mockMatchingUser]),
+    );
+
+    const { getByLabelText, getByText } = render(
+      <MentionAutocompleteCombobox
+        onSelect={mockOnSelect}
+        onSearchTermChange={mockOnSearchtermChange}
+        fetchSuggestions={mockFetchSuggestions}
+        placementCoords={mockCoords}
+      />,
+    );
+
+    expect(mockFetchSuggestions.mock.calls.length).toBe(0);
+
+    const input = getByLabelText('mention user');
+    userEvent.type(input, 'use');
+    expect(mockFetchSuggestions.mock.calls.length).toBe(1);
+
+    await waitFor(() => expect(getByText('User One')).toBeInTheDocument());
+    expect(getByText('@user_1')).toBeInTheDocument();
+  });
+
+  it('should display empty matches state', async () => {
+    const { getByText, getByLabelText } = render(
+      <MentionAutocompleteCombobox
+        fetchSuggestions={() => Promise.resolve([])}
+        onSelect={mockOnSelect}
+        onSearchTermChange={mockOnSearchtermChange}
+        placementCoords={mockCoords}
+      />,
+    );
+
+    const input = getByLabelText('mention user');
+    userEvent.type(input, 'us');
+
+    await waitFor(() =>
+      expect(getByText('No results found')).toBeInTheDocument(),
+    );
+  });
+});
diff --git a/app/javascript/crayons/MentionAutocomplete/__tests__/__snapshots__/MentionAutocompleteCombobox.test.jsx.snap b/app/javascript/crayons/MentionAutocomplete/__tests__/__snapshots__/MentionAutocompleteCombobox.test.jsx.snap
new file mode 100644
index 000000000..e4060b4df
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/__tests__/__snapshots__/MentionAutocompleteCombobox.test.jsx.snap
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`<MentionAutocomplete /> should render 1`] = `"<div class=\\"crayons-autocomplete\\" data-reach-combobox=\\"\\" data-state=\\"idle\\"><input aria-autocomplete=\\"both\\" aria-controls=\\"listbox--5\\" aria-expanded=\\"false\\" aria-haspopup=\\"listbox\\" aria-label=\\"mention user\\" role=\\"combobox\\" style=\\"opacity: 0.000001;\\" data-reach-combobox-input=\\"\\" data-state=\\"idle\\"></div>"`;
diff --git a/app/javascript/crayons/MentionAutocomplete/index.js b/app/javascript/crayons/MentionAutocomplete/index.js
new file mode 100644
index 000000000..12324f1f4
--- /dev/null
+++ b/app/javascript/crayons/MentionAutocomplete/index.js
@@ -0,0 +1 @@
+export * from './MentionAutocomplete';
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/MentionAutocompleteTextArea.jsx b/app/javascript/crayons/MentionAutocompleteTextArea/MentionAutocompleteTextArea.jsx
deleted file mode 100644
index d9458ec62..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/MentionAutocompleteTextArea.jsx
+++ /dev/null
@@ -1,265 +0,0 @@
-import { h, Fragment } from 'preact';
-import { useState, useEffect, useRef, useLayoutEffect } from 'preact/hooks';
-import PropTypes from 'prop-types';
-import {
-  Combobox,
-  ComboboxInput,
-  ComboboxPopover,
-  ComboboxList,
-  ComboboxOption,
-} from '@reach/combobox';
-import '@reach/combobox/styles.css';
-import { getMentionWordData, getCursorXY } from '@utilities/textAreaUtils';
-import { useMediaQuery, BREAKPOINTS } from '@components/useMediaQuery';
-
-const MIN_SEARCH_CHARACTERS = 2;
-const MAX_RESULTS_DISPLAYED = 6;
-
-const UserListItemContent = ({ user }) => {
-  return (
-    <Fragment>
-      <span className="crayons-avatar crayons-avatar--l mr-2 shrink-0">
-        <img
-          src={user.profile_image_90}
-          alt=""
-          className="crayons-avatar__image "
-        />
-      </span>
-
-      <div>
-        <p className="crayons-autocomplete__name">{user.name}</p>
-        <p className="crayons-autocomplete__username">{`@${user.username}`}</p>
-      </div>
-    </Fragment>
-  );
-};
-
-/**
- * A component for dynamically searching for users and displaying results in a dropdown.
- * This component will replace the textarea passed in props, copying all styles and attributes, and allowing for progressive enhancement
- *
- * @param {object} props
- * @param {element} props.replaceElement The textarea DOM element that should be replaced
- * @param {function} props.fetchSuggestions The async call to use for the search
- *
- * @example
- * <MentionAutocompleteCombobox
- *    replaceElement={textAreaRef.current}
- *    fetchSuggestions={fetchUsersByUsername}
- * />
- */
-export const MentionAutocompleteTextArea = ({
-  replaceElement,
-  fetchSuggestions,
-}) => {
-  const [textContent, setTextContent] = useState('');
-  const [searchTerm, setSearchTerm] = useState('');
-  const [cachedSearches, setCachedSearches] = useState({});
-  const [dropdownPositionPoints, setDropdownPositionPoints] = useState({
-    x: 0,
-    y: 0,
-  });
-  const [selectionInsertIndex, setSelectionInsertIndex] = useState(0);
-  const [users, setUsers] = useState([]);
-  const [cursorPosition, setCursorPosition] = useState(null);
-  const [ariaHelperText, setAriaHelperText] = useState('');
-
-  const isSmallScreen = useMediaQuery(`(max-width: ${BREAKPOINTS.Small}px)`);
-
-  const inputRef = useRef(null);
-
-  useEffect(() => {
-    if (searchTerm.length >= MIN_SEARCH_CHARACTERS) {
-      if (cachedSearches[searchTerm]) {
-        setUsers(cachedSearches[searchTerm]);
-        return;
-      }
-
-      fetchSuggestions(searchTerm).then(({ result: fetchedUsers }) => {
-        const resultLength = Math.min(
-          fetchedUsers.length,
-          MAX_RESULTS_DISPLAYED,
-        );
-
-        const results = fetchedUsers.slice(0, resultLength);
-
-        setCachedSearches({
-          ...cachedSearches,
-          [searchTerm]: results,
-        });
-
-        setUsers(results);
-
-        // Let screen reader users know a list has populated
-        const requiresAriaLiveAnnouncement =
-          !ariaHelperText && fetchedUsers.length > 0;
-
-        if (requiresAriaLiveAnnouncement) {
-          setAriaHelperText(
-            `Mention user, ${fetchedUsers.length} results found`,
-          );
-        }
-      });
-    }
-  }, [searchTerm, fetchSuggestions, cachedSearches, ariaHelperText]);
-
-  useLayoutEffect(() => {
-    const popover = document.getElementById('mention-autocomplete-popover');
-    if (!popover) {
-      return;
-    }
-
-    const closeOnClickOutsideListener = (event) => {
-      if (!popover.contains(event.target)) {
-        // User clicked outside, reset to not searching state
-        setSearchTerm('');
-        setAriaHelperText('');
-        setUsers([]);
-      }
-    };
-
-    document.addEventListener('click', closeOnClickOutsideListener);
-
-    return () =>
-      document.removeEventListener('click', closeOnClickOutsideListener);
-  }, [searchTerm]);
-
-  useLayoutEffect(() => {
-    inputRef.current.focus();
-    inputRef.current.setSelectionRange(cursorPosition, cursorPosition - 1);
-  }, [cursorPosition]);
-
-  const handleValueChange = ({ target: { value } }) => {
-    setTextContent(value);
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputRef.current,
-    );
-
-    const { selectionStart } = inputRef.current;
-
-    if (isUserMention) {
-      // search term begins after the @ character
-      const searchTermStartPosition = indexOfMentionStart + 1;
-
-      const mentionText = value.substring(
-        searchTermStartPosition,
-        selectionStart,
-      );
-
-      const { x: cursorX, y } = getCursorXY(
-        inputRef.current,
-        indexOfMentionStart,
-      );
-      const textAreaX = inputRef.current.offsetLeft;
-
-      // On small screens always show dropdown at start of textarea
-      const dropdownX = isSmallScreen ? textAreaX : cursorX;
-
-      setDropdownPositionPoints({ x: dropdownX, y });
-      setSearchTerm(mentionText);
-      setSelectionInsertIndex(searchTermStartPosition);
-    } else if (searchTerm) {
-      // User has moved away from an in-progress @mention - clear current search
-      setSearchTerm('');
-      setAriaHelperText('');
-      setUsers([]);
-    }
-  };
-
-  const handleSelect = (username) => {
-    const textWithSelection = `${textContent.substring(
-      0,
-      selectionInsertIndex,
-    )}${username}${textContent.substring(inputRef.current.selectionStart)}`;
-
-    // Clear the current search
-    setSearchTerm('');
-    setUsers([]);
-    setAriaHelperText('');
-
-    // Update the text area value
-    setTextContent(textWithSelection);
-
-    // Update the cursor to directly after the selection
-    const newCursorPosition = selectionInsertIndex + username.length + 1;
-    setCursorPosition(newCursorPosition);
-  };
-
-  useLayoutEffect(() => {
-    if (inputRef.current) {
-      const attributes = replaceElement.attributes;
-      Object.keys(attributes).forEach((attributeKey) => {
-        inputRef.current.setAttribute(
-          attributes[attributeKey].name,
-          attributes[attributeKey].value,
-        );
-      });
-
-      inputRef.current.style.cssText = document.defaultView.getComputedStyle(
-        replaceElement,
-        '',
-      ).cssText;
-
-      // We need to manually remove the element, as Preact's diffing algorithm won't replace it in render
-      replaceElement.remove();
-      inputRef.current.focus();
-    }
-  }, [replaceElement]);
-
-  return (
-    <Fragment>
-      <div aria-live="polite" class="screen-reader-only">
-        {ariaHelperText}
-      </div>
-      <Combobox
-        id="combobox-container"
-        onSelect={handleSelect}
-        className="crayons-autocomplete"
-      >
-        <ComboboxInput
-          ref={inputRef}
-          value={textContent}
-          data-mention-autocomplete-active="true"
-          as="textarea"
-          autocomplete={false}
-          onChange={handleValueChange}
-        />
-        {searchTerm && (
-          <ComboboxPopover
-            className="crayons-autocomplete__popover"
-            id="mention-autocomplete-popover"
-            style={{
-              position: 'absolute',
-              top: `calc(${dropdownPositionPoints.y}px + 1.5rem)`,
-              left: `${dropdownPositionPoints.x}px`,
-            }}
-          >
-            {users.length > 0 ? (
-              <ComboboxList>
-                {users.map((user) => (
-                  <ComboboxOption
-                    value={user.username}
-                    className="crayons-autocomplete__option flex items-center"
-                  >
-                    <UserListItemContent user={user} />
-                  </ComboboxOption>
-                ))}
-              </ComboboxList>
-            ) : (
-              <span className="crayons-autocomplete__empty">
-                {searchTerm.length >= MIN_SEARCH_CHARACTERS
-                  ? 'No results found'
-                  : 'Type to search for a user'}
-              </span>
-            )}
-          </ComboboxPopover>
-        )}
-      </Combobox>
-    </Fragment>
-  );
-};
-
-MentionAutocompleteTextArea.propTypes = {
-  replaceElement: PropTypes.node.isRequired,
-  fetchSuggestions: PropTypes.func.isRequired,
-};
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/MentionAutocompleteTextArea.stories.jsx b/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/MentionAutocompleteTextArea.stories.jsx
deleted file mode 100644
index e7a4409a9..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/MentionAutocompleteTextArea.stories.jsx
+++ /dev/null
@@ -1,99 +0,0 @@
-import { h, createRef, render } from 'preact';
-import { MentionAutocompleteTextArea } from '../MentionAutocompleteTextArea';
-import notes from './mention-autocomplete.md';
-
-export default {
-  title: 'Components/MentionAutocompleteTextArea',
-  parameters: { notes },
-};
-
-async function fetchUsers(searchTerm) {
-  const exampleApiResult = [
-    {
-      username: 'user_one',
-      name: 'User One First Name Last Name',
-      profile_image_90: '/images/apple-icon.png',
-    },
-    {
-      username: 'user_two',
-      name: 'User Two',
-      profile_image_90: '/images/apple-icon.png',
-    },
-    {
-      username: 'user_three',
-      name: 'User Three',
-      profile_image_90: '/images/apple-icon.png',
-    },
-    {
-      username: 'user_four',
-      name: 'User Four',
-      profile_image_90: '/images/apple-icon.png',
-    },
-    {
-      username: 'user_five',
-      name: 'User Five',
-      profile_image_90: '/images/apple-icon.png',
-    },
-    {
-      username: 'user_six',
-      name: 'User Six First Name Last Name Longer',
-      profile_image_90: '/images/apple-icon.png',
-    },
-  ];
-
-  return {
-    result: exampleApiResult.filter((user) =>
-      user.username.includes(searchTerm),
-    ),
-  };
-}
-
-export const Default = () => {
-  const textAreaRef = createRef(null);
-
-  const handleAreaFocused = () => {
-    const container = document.getElementById('story-container');
-    if (
-      textAreaRef.current &&
-      !container.getAttribute('autocomplete-initialized')
-    ) {
-      const storybookElement = textAreaRef.current;
-
-      render(
-        <MentionAutocompleteTextArea
-          replaceElement={storybookElement}
-          fetchSuggestions={fetchUsers}
-          labelId="storybook-autocomplete-label"
-        />,
-        container,
-        storybookElement,
-      );
-
-      container.setAttribute('autocomplete-initialized', 'true');
-    }
-  };
-
-  return (
-    <div id="story-container">
-      <label id="storybook-autocomplete-label">
-        Enter text and type '@us' to start triggering search results
-        <div>
-          <textarea
-            ref={textAreaRef}
-            aria-labelledby="storybook-autocomplete-label"
-            onFocus={handleAreaFocused}
-            style={{
-              width: '500px',
-              maxWidth: '100%',
-              minHeight: '200px',
-            }}
-          />
-        </div>
-      </label>
-    </div>
-  );
-};
-
-Default.story = {
-  name: 'default',
-};
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/mention-autocomplete.md b/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/mention-autocomplete.md
deleted file mode 100644
index d28a9ec38..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/__stories__/mention-autocomplete.md
+++ /dev/null
@@ -1,18 +0,0 @@
-## Mention autocomplete
-
-The `MentionAutocompleteTextArea` component uses the [Reach UI Combobox](https://reach.tech/combobox/) under the hood. It works by _replacing_ the textarea you pass in props with one enhanced with the `@mention` functionality.
-
-The autocomplete will begin fetching suggestions once a user has typed `@` plus at least two characters. A user&apos;s selection is confirmed when they either:
-
-- Click on a search option
-- Hit enter on a search option
-- Click away from the dropdown
-- Enter space to move away from the autocomplete
-
-### Mention autocomplete accessibility
-
-The component replaces the given textarea with one generated using [Reach UI Combobox](https://reach.tech/combobox/). The underlying behavior then conforms to the [WAI_ARIA guidelines on comboboxes](https://www.w3.org/TR/wai-aria-practices-1.2/#combobox).
-
-An `aria-live` region communicates to a screen reader user when the list has been populated with suggestions.
-
-Please note: When using the `MentionAutocompleteTextArea`, you must have either an `aria-labelledby` or `aria-label` attribute on the textarea you pass as a prop. These attributes are copied across to the Reach UI Combobox input, ensuring it is labelled correctly for accessibility.
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/MentionAutocompleteTextArea.test.jsx b/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/MentionAutocompleteTextArea.test.jsx
deleted file mode 100644
index 9c0d56a3f..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/MentionAutocompleteTextArea.test.jsx
+++ /dev/null
@@ -1,52 +0,0 @@
-import { h } from 'preact';
-import { render } from '@testing-library/preact';
-import '@testing-library/jest-dom';
-import { MentionAutocompleteTextArea } from '../MentionAutocompleteTextArea';
-
-describe('<MentionAutocompleteTextArea />', () => {
-  const textArea = document.createElement('textarea');
-  textArea.setAttribute('aria-label', 'test text area');
-  textArea.setAttribute('id', 'test-text-area');
-
-  beforeAll(() => {
-    global.window.matchMedia = jest.fn((query) => {
-      return {
-        matches: false,
-        media: query,
-        addListener: jest.fn(),
-        removeListener: jest.fn(),
-      };
-    });
-  });
-
-  beforeEach(() => {
-    document.body.appendChild(textArea);
-  });
-
-  it('should render', () => {
-    const { container } = render(
-      <MentionAutocompleteTextArea
-        replaceElement={textArea}
-        fetchSuggestions={async () => ({ result: [] })}
-      />,
-    );
-
-    expect(container.innerHTML).toMatchSnapshot();
-  });
-
-  it('should replace the given textarea with a combobox textarea', () => {
-    const { getByRole, getAllByLabelText } = render(
-      <MentionAutocompleteTextArea
-        replaceElement={textArea}
-        fetchSuggestions={async () => ({ result: [] })}
-      />,
-    );
-
-    const combobox = getByRole('combobox');
-    expect(combobox).toBeInTheDocument();
-    expect(combobox.id).toEqual('test-text-area');
-    expect(combobox.getAttribute('aria-label')).toEqual('test text area');
-
-    expect(getAllByLabelText('test text area')).toHaveLength(1);
-  });
-});
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/__snapshots__/MentionAutocompleteTextArea.test.jsx.snap b/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/__snapshots__/MentionAutocompleteTextArea.test.jsx.snap
deleted file mode 100644
index 9859b017f..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/__tests__/__snapshots__/MentionAutocompleteTextArea.test.jsx.snap
+++ /dev/null
@@ -1,3 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`<MentionAutocompleteTextArea /> should render 1`] = `"<div aria-live=\\"polite\\" class=\\"screen-reader-only\\"></div><div id=\\"combobox-container\\" class=\\"crayons-autocomplete\\" data-reach-combobox=\\"\\" data-state=\\"idle\\"><textarea aria-autocomplete=\\"both\\" aria-controls=\\"listbox--combobox-container\\" aria-expanded=\\"false\\" aria-haspopup=\\"listbox\\" role=\\"combobox\\" data-mention-autocomplete-active=\\"true\\" data-reach-combobox-input=\\"\\" data-state=\\"idle\\" aria-label=\\"test text area\\" id=\\"test-text-area\\" style=\\"font: -webkit-small-control; text-rendering: auto; letter-spacing: normal; word-spacing: normal; line-height: normal; text-transform: none; text-indent: 0; text-shadow: none; display: inline-block; text-align: start; background-color: white; border: 1px solid; flex-direction: column; resize: auto; cursor: auto; padding: 2px; white-space: pre-wrap; word-wrap: break-word; visibility: visible;\\"></textarea></div>"`;
diff --git a/app/javascript/crayons/MentionAutocompleteTextArea/index.js b/app/javascript/crayons/MentionAutocompleteTextArea/index.js
deleted file mode 100644
index 566452145..000000000
--- a/app/javascript/crayons/MentionAutocompleteTextArea/index.js
+++ /dev/null
@@ -1 +0,0 @@
-export * from './MentionAutocompleteTextArea';
diff --git a/app/javascript/utilities/__tests__/textAreaUtils.test.js b/app/javascript/utilities/__tests__/textAreaUtils.test.js
deleted file mode 100644
index e8e17979f..000000000
--- a/app/javascript/utilities/__tests__/textAreaUtils.test.js
+++ /dev/null
@@ -1,68 +0,0 @@
-import { getMentionWordData } from '../textAreaUtils';
-
-describe('getMentionWordData', () => {
-  it('returns userMention false for cursor at start of input', () => {
-    const inputState = {
-      selectionStart: 0,
-      value: 'text with @mention',
-    };
-
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputState,
-    );
-    expect(isUserMention).toBe(false);
-    expect(indexOfMentionStart).toEqual(-1);
-  });
-
-  it('returns userMention false for empty input value', () => {
-    const inputState = {
-      selectionStart: 10,
-      value: '',
-    };
-
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputState,
-    );
-    expect(isUserMention).toBe(false);
-    expect(indexOfMentionStart).toEqual(-1);
-  });
-
-  it('returns userMention false if no @ symbol exists at start of word', () => {
-    const inputState = {
-      selectionStart: 13,
-      value: 'text with no mention',
-    };
-
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputState,
-    );
-    expect(isUserMention).toBe(false);
-    expect(indexOfMentionStart).toEqual(-1);
-  });
-
-  it('returns userMention true and correct index for an @ mention at beginning of input', () => {
-    const inputState = {
-      selectionStart: 3,
-      value: '@mention',
-    };
-
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputState,
-    );
-    expect(isUserMention).toBe(true);
-    expect(indexOfMentionStart).toEqual(0);
-  });
-
-  it('returns userMention true and correct index for @ mention in middle of input', () => {
-    const inputState = {
-      selectionStart: 13,
-      value: 'text with @mention',
-    };
-
-    const { isUserMention, indexOfMentionStart } = getMentionWordData(
-      inputState,
-    );
-    expect(isUserMention).toBe(true);
-    expect(indexOfMentionStart).toEqual(10);
-  });
-});
diff --git a/app/javascript/utilities/textAreaUtils.js b/app/javascript/utilities/textAreaUtils.js
index 4768c44ed..5efbb07d2 100644
--- a/app/javascript/utilities/textAreaUtils.js
+++ b/app/javascript/utilities/textAreaUtils.js
@@ -11,25 +11,15 @@
  * const coordinates = getCursorXY(elementRef.current, elementRef.current.selectionStart)
  */
 export const getCursorXY = (input, selectionPoint) => {
-  const bodyRect = document.body.getBoundingClientRect();
-  const elementRect = input.getBoundingClientRect();
-
-  const inputY = elementRect.top - bodyRect.top;
-  const inputX = elementRect.left - bodyRect.left;
+  const { offsetLeft: inputX, offsetTop: inputY } = input;
 
   // create a dummy element with the computed style of the input
-  const div = document.createElement('div');
+  const div = top.document.createElement('div');
   const copyStyle = getComputedStyle(input);
   for (const prop of copyStyle) {
     div.style[prop] = copyStyle[prop];
   }
 
-  // set the div to the correct position
-  div.style['position'] = 'absolute';
-  div.style['top'] = `${inputY}px`;
-  div.style['left'] = `${inputX}px`;
-  div.style['opacity'] = 0;
-
   // replace whitespace with '.' when filling the dummy element if it's a single line <input/>
   const swap = '.';
   const inputValue =
@@ -43,75 +33,22 @@ export const getCursorXY = (input, selectionPoint) => {
   if (input.tagName === 'INPUT') div.style.width = 'auto';
 
   // marker element to obtain caret position
-  const span = document.createElement('span');
+  const span = top.document.createElement('span');
   // give the span the textContent of remaining content so that the recreated dummy element is as close as possible
   span.textContent = inputValue.substr(selectionPoint) || '.';
 
   // append the span marker to the div and the dummy element to the body
   div.appendChild(span);
-  document.body.appendChild(div);
+  top.document.body.appendChild(div);
 
   // get the marker position, this is the caret position top and left relative to the input
   const { offsetLeft: spanX, offsetTop: spanY } = span;
 
   // remove dummy element
-  document.body.removeChild(div);
-
+  top.document.body.removeChild(div);
   // return object with the x and y of the caret. account for input positioning so that you don't need to wrap the input
   return {
     x: inputX + spanX,
     y: inputY + spanY,
   };
 };
-
-/**
- * A helper function that searches back to the beginning of the currently typed word (indicated by cursor position) and verifies whether it begins with an '@' symbol for user mention
- *
- * @param {element} textArea The text area or input to inspect the current word of
- * @returns {{isUserMention: boolean, indexOfMentionStart: number}} Object with the word's mention data
- *
- * @example
- * const { isUserMention, indexOfMentionStart } = getMentionWordData(textArea);
- * if (isUserMention) {
- *  // Do something
- * }
- */
-export const getMentionWordData = (textArea) => {
-  const { selectionStart, value: valueBeforeKeystroke } = textArea;
-
-  if (selectionStart === 0 || valueBeforeKeystroke === '') {
-    return {
-      isUserMention: false,
-      indexOfMentionStart: -1,
-    };
-  }
-
-  const indexOfAutocompleteStart = getIndexOfCurrentWordAutocompleteSymbol(
-    valueBeforeKeystroke,
-    selectionStart,
-  );
-
-  return {
-    isUserMention: indexOfAutocompleteStart !== -1,
-    indexOfMentionStart: indexOfAutocompleteStart,
-  };
-};
-
-const getIndexOfCurrentWordAutocompleteSymbol = (content, selectionIndex) => {
-  const currentCharacter = content.charAt(selectionIndex);
-  const previousCharacter = content.charAt(selectionIndex - 1);
-
-  if (
-    selectionIndex !== 0 &&
-    previousCharacter !== ' ' &&
-    previousCharacter !== ''
-  ) {
-    return getIndexOfCurrentWordAutocompleteSymbol(content, selectionIndex - 1);
-  }
-
-  if (currentCharacter === '@') {
-    return selectionIndex;
-  }
-
-  return -1;
-};
diff --git a/config/webpack/environment.js b/config/webpack/environment.js
index ed747673c..842312300 100644
--- a/config/webpack/environment.js
+++ b/config/webpack/environment.js
@@ -26,8 +26,6 @@ environment.splitChunks((config) => {
           __dirname,
           '../../app/javascript/shared/components',
         ),
-        react: 'preact/compat',
-        'react-dom': 'preact/compat',
       },
     },
   };