diff --git a/ts/components/ConversationList.tsx b/ts/components/ConversationList.tsx
index a314d5e55..3661b5a42 100644
--- a/ts/components/ConversationList.tsx
+++ b/ts/components/ConversationList.tsx
@@ -25,6 +25,7 @@ import { ContactListItem } from './conversationList/ContactListItem';
 import type { ContactCheckboxDisabledReason } from './conversationList/ContactCheckbox';
 import { ContactCheckbox as ContactCheckboxComponent } from './conversationList/ContactCheckbox';
 import { PhoneNumberCheckbox as PhoneNumberCheckboxComponent } from './conversationList/PhoneNumberCheckbox';
+import { UsernameCheckbox as UsernameCheckboxComponent } from './conversationList/UsernameCheckbox';
 import { CreateNewGroupButton } from './conversationList/CreateNewGroupButton';
 import { StartNewConversation as StartNewConversationComponent } from './conversationList/StartNewConversation';
 import { SearchResultsLoadingFakeHeader as SearchResultsLoadingFakeHeaderComponent } from './conversationList/SearchResultsLoadingFakeHeader';
@@ -32,19 +33,20 @@ import { SearchResultsLoadingFakeRow as SearchResultsLoadingFakeRowComponent } f
 import { UsernameSearchResultListItem } from './conversationList/UsernameSearchResultListItem';
 
 export enum RowType {
-  ArchiveButton,
-  Blank,
-  Contact,
-  ContactCheckbox,
-  PhoneNumberCheckbox,
-  Conversation,
-  CreateNewGroup,
-  Header,
-  MessageSearchResult,
-  SearchResultsLoadingFakeHeader,
-  SearchResultsLoadingFakeRow,
-  StartNewConversation,
-  UsernameSearchResult,
+  ArchiveButton = 'ArchiveButton',
+  Blank = 'Blank',
+  Contact = 'Contact',
+  ContactCheckbox = 'ContactCheckbox',
+  PhoneNumberCheckbox = 'PhoneNumberCheckbox',
+  UsernameCheckbox = 'UsernameCheckbox',
+  Conversation = 'Conversation',
+  CreateNewGroup = 'CreateNewGroup',
+  Header = 'Header',
+  MessageSearchResult = 'MessageSearchResult',
+  SearchResultsLoadingFakeHeader = 'SearchResultsLoadingFakeHeader',
+  SearchResultsLoadingFakeRow = 'SearchResultsLoadingFakeRow',
+  StartNewConversation = 'StartNewConversation',
+  UsernameSearchResult = 'UsernameSearchResult',
 }
 
 type ArchiveButtonRowType = {
@@ -74,6 +76,13 @@ type PhoneNumberCheckboxRowType = {
   isFetching: boolean;
 };
 
+type UsernameCheckboxRowType = {
+  type: RowType.UsernameCheckbox;
+  username: string;
+  isChecked: boolean;
+  isFetching: boolean;
+};
+
 type ConversationRowType = {
   type: RowType.Conversation;
   conversation: ConversationListItemPropsType;
@@ -119,6 +128,7 @@ export type Row =
   | ContactRowType
   | ContactCheckboxRowType
   | PhoneNumberCheckboxRowType
+  | UsernameCheckboxRowType
   | ConversationRowType
   | CreateNewGroupRowType
   | MessageRowType
@@ -283,6 +293,23 @@ export const ConversationList: React.FC<PropsType> = ({
             />
           );
           break;
+        case RowType.UsernameCheckbox:
+          result = (
+            <UsernameCheckboxComponent
+              username={row.username}
+              lookupConversationWithoutUuid={lookupConversationWithoutUuid}
+              showUserNotFoundModal={showUserNotFoundModal}
+              setIsFetchingUUID={setIsFetchingUUID}
+              toggleConversationInChooseMembers={conversationId =>
+                onClickContactCheckbox(conversationId, undefined)
+              }
+              isChecked={row.isChecked}
+              isFetching={row.isFetching}
+              i18n={i18n}
+              theme={theme}
+            />
+          );
+          break;
         case RowType.Conversation: {
           const itemProps = pick(row.conversation, [
             'acceptedMessageRequest',
diff --git a/ts/components/LeftPane.stories.tsx b/ts/components/LeftPane.stories.tsx
index c34c5e027..a19b7b502 100644
--- a/ts/components/LeftPane.stories.tsx
+++ b/ts/components/LeftPane.stories.tsx
@@ -883,6 +883,7 @@ export const ChooseGroupMembersPartialPhoneNumber = (): JSX.Element => (
         candidateContacts: [],
         isShowingRecommendedGroupSizeModal: false,
         isShowingMaximumGroupSizeModal: false,
+        isUsernamesEnabled: true,
         searchTerm: '+1(212) 555',
         regionCode: 'US',
         selectedContacts: [],
@@ -904,6 +905,7 @@ export const ChooseGroupMembersValidPhoneNumber = (): JSX.Element => (
         candidateContacts: [],
         isShowingRecommendedGroupSizeModal: false,
         isShowingMaximumGroupSizeModal: false,
+        isUsernamesEnabled: true,
         searchTerm: '+1(212) 555 5454',
         regionCode: 'US',
         selectedContacts: [],
@@ -916,6 +918,28 @@ ChooseGroupMembersValidPhoneNumber.story = {
   name: 'Choose Group Members: Valid phone number',
 };
 
+export const ChooseGroupMembersUsername = (): JSX.Element => (
+  <LeftPane
+    {...useProps({
+      modeSpecificProps: {
+        mode: LeftPaneMode.ChooseGroupMembers,
+        uuidFetchState: {},
+        candidateContacts: [],
+        isShowingRecommendedGroupSizeModal: false,
+        isShowingMaximumGroupSizeModal: false,
+        isUsernamesEnabled: true,
+        searchTerm: '@signal',
+        regionCode: 'US',
+        selectedContacts: [],
+      },
+    })}
+  />
+);
+
+ChooseGroupMembersUsername.story = {
+  name: 'Choose Group Members: username',
+};
+
 export const GroupMetadataNoTimer = (): JSX.Element => (
   <LeftPane
     {...useProps({
diff --git a/ts/components/conversation/conversation-details/AddGroupMembersModal.stories.tsx b/ts/components/conversation/conversation-details/AddGroupMembersModal.stories.tsx
index 9f310454c..9b9335672 100644
--- a/ts/components/conversation/conversation-details/AddGroupMembersModal.stories.tsx
+++ b/ts/components/conversation/conversation-details/AddGroupMembersModal.stories.tsx
@@ -68,6 +68,7 @@ const createProps = (
         i18n={i18n}
         lookupConversationWithoutUuid={lookupConversationWithoutUuid}
         showUserNotFoundModal={action('showUserNotFoundModal')}
+        isUsernamesEnabled
       />
     );
   },
diff --git a/ts/components/conversation/conversation-details/AddGroupMembersModal/ChooseGroupMembersModal.tsx b/ts/components/conversation/conversation-details/AddGroupMembersModal/ChooseGroupMembersModal.tsx
index c567440ac..ffe594737 100644
--- a/ts/components/conversation/conversation-details/AddGroupMembersModal/ChooseGroupMembersModal.tsx
+++ b/ts/components/conversation/conversation-details/AddGroupMembersModal/ChooseGroupMembersModal.tsx
@@ -14,6 +14,7 @@ import type { MeasuredComponentProps } from 'react-measure';
 import Measure from 'react-measure';
 
 import type { LocalizerType, ThemeType } from '../../../../types/Util';
+import { getUsernameFromSearch } from '../../../../types/Username';
 import { assert } from '../../../../util/assert';
 import { refMerger } from '../../../../util/refMerger';
 import { useRestoreFocus } from '../../../../hooks/useRestoreFocus';
@@ -27,7 +28,10 @@ import type {
   UUIDFetchStateKeyType,
   UUIDFetchStateType,
 } from '../../../../util/uuidFetchState';
-import { isFetchingByE164 } from '../../../../util/uuidFetchState';
+import {
+  isFetchingByE164,
+  isFetchingByUsername,
+} from '../../../../util/uuidFetchState';
 import { ModalHost } from '../../../ModalHost';
 import { ContactPills } from '../../../ContactPills';
 import { ContactPill } from '../../../ContactPill';
@@ -53,6 +57,7 @@ export type StatePropsType = {
   removeSelectedContact: (_: string) => void;
   setSearchTerm: (_: string) => void;
   toggleSelectedContact: (conversationId: string) => void;
+  isUsernamesEnabled: boolean;
 } & Pick<
   LookupConversationWithoutUuidActionsType,
   'lookupConversationWithoutUuid'
@@ -83,6 +88,7 @@ export const ChooseGroupMembersModal: FunctionComponent<PropsType> = ({
   toggleSelectedContact,
   lookupConversationWithoutUuid,
   showUserNotFoundModal,
+  isUsernamesEnabled,
 }) => {
   const [focusRef] = useRestoreFocus();
 
@@ -99,6 +105,21 @@ export const ChooseGroupMembersModal: FunctionComponent<PropsType> = ({
     phoneNumber &&
     candidateContacts.every(contact => contact.e164 !== phoneNumber.e164);
 
+  let username: string | undefined;
+  let isUsernameChecked = false;
+  let isUsernameVisible = false;
+  if (!phoneNumber && isUsernamesEnabled) {
+    username = getUsernameFromSearch(searchTerm);
+
+    isUsernameChecked = selectedContacts.some(
+      contact => contact.username === username
+    );
+
+    isUsernameVisible = candidateContacts.every(
+      contact => contact.username !== username
+    );
+  }
+
   const inputRef = useRef<null | HTMLInputElement>(null);
 
   const numberOfContactsAlreadyInGroup = conversationIdsAlreadyInGroup.size;
@@ -157,19 +178,24 @@ export const ChooseGroupMembersModal: FunctionComponent<PropsType> = ({
   if (filteredContacts.length) {
     rowCount += filteredContacts.length;
   }
-  if (isPhoneNumberVisible) {
+  if (isPhoneNumberVisible || isUsernameVisible) {
     // "Contacts" header
     if (filteredContacts.length) {
       rowCount += 1;
     }
 
     // "Find by phone number" + phone number
+    // or
+    // "Find by username" + username
     rowCount += 2;
   }
   const getRow = (index: number): undefined | Row => {
     let virtualIndex = index;
 
-    if (isPhoneNumberVisible && filteredContacts.length) {
+    if (
+      (isPhoneNumberVisible || isUsernameVisible) &&
+      filteredContacts.length
+    ) {
       if (virtualIndex === 0) {
         return {
           type: RowType.Header,
@@ -221,6 +247,24 @@ export const ChooseGroupMembersModal: FunctionComponent<PropsType> = ({
       virtualIndex -= 2;
     }
 
+    if (username) {
+      if (virtualIndex === 0) {
+        return {
+          type: RowType.Header,
+          i18nKey: 'findByUsernameHeader',
+        };
+      }
+      if (virtualIndex === 1) {
+        return {
+          type: RowType.UsernameCheckbox,
+          isChecked: isUsernameChecked,
+          isFetching: isFetchingByUsername(uuidFetchState, username),
+          username,
+        };
+      }
+      virtualIndex -= 2;
+    }
+
     return undefined;
   };
 
diff --git a/ts/components/conversation/conversation-details/ConversationDetails.stories.tsx b/ts/components/conversation/conversation-details/ConversationDetails.stories.tsx
index f1d600721..18133f2f9 100644
--- a/ts/components/conversation/conversation-details/ConversationDetails.stories.tsx
+++ b/ts/components/conversation/conversation-details/ConversationDetails.stories.tsx
@@ -110,6 +110,7 @@ const createProps = (hasGroupLink = false, expireTimer?: number): Props => ({
         i18n={i18n}
         lookupConversationWithoutUuid={makeFakeLookupConversationWithoutUuid()}
         showUserNotFoundModal={action('showUserNotFoundModal')}
+        isUsernamesEnabled
       />
     );
   },
diff --git a/ts/components/conversationList/ContactListItem.tsx b/ts/components/conversationList/ContactListItem.tsx
index 6937ae86b..6863e5f40 100644
--- a/ts/components/conversationList/ContactListItem.tsx
+++ b/ts/components/conversationList/ContactListItem.tsx
@@ -30,6 +30,7 @@ export type ContactListItemConversationType = Pick<
   | 'title'
   | 'type'
   | 'unblurredAvatarPath'
+  | 'username'
   | 'e164'
 >;
 
diff --git a/ts/components/conversationList/UsernameCheckbox.tsx b/ts/components/conversationList/UsernameCheckbox.tsx
new file mode 100644
index 000000000..28c954703
--- /dev/null
+++ b/ts/components/conversationList/UsernameCheckbox.tsx
@@ -0,0 +1,84 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { FunctionComponent } from 'react';
+import React from 'react';
+
+import { BaseConversationListItem } from './BaseConversationListItem';
+import type { LocalizerType, ThemeType } from '../../types/Util';
+import { AvatarColors } from '../../types/Colors';
+import type { LookupConversationWithoutUuidActionsType } from '../../util/lookupConversationWithoutUuid';
+
+export type PropsDataType = {
+  username: string;
+  isChecked: boolean;
+  isFetching: boolean;
+};
+
+type PropsHousekeepingType = {
+  i18n: LocalizerType;
+  theme: ThemeType;
+  toggleConversationInChooseMembers: (conversationId: string) => void;
+} & LookupConversationWithoutUuidActionsType;
+
+type PropsType = PropsDataType & PropsHousekeepingType;
+
+export const UsernameCheckbox: FunctionComponent<PropsType> = React.memo(
+  function UsernameCheckbox({
+    username,
+    isChecked,
+    isFetching,
+    theme,
+    i18n,
+    lookupConversationWithoutUuid,
+    showUserNotFoundModal,
+    setIsFetchingUUID,
+    toggleConversationInChooseMembers,
+  }) {
+    const onClickItem = React.useCallback(async () => {
+      if (isFetching) {
+        return;
+      }
+
+      const conversationId = await lookupConversationWithoutUuid({
+        showUserNotFoundModal,
+        setIsFetchingUUID,
+
+        type: 'username',
+        username,
+      });
+
+      if (conversationId !== undefined) {
+        toggleConversationInChooseMembers(conversationId);
+      }
+    }, [
+      isFetching,
+      toggleConversationInChooseMembers,
+      lookupConversationWithoutUuid,
+      showUserNotFoundModal,
+      setIsFetchingUUID,
+      username,
+    ]);
+
+    const title = i18n('at-username', { username });
+
+    return (
+      <BaseConversationListItem
+        acceptedMessageRequest={false}
+        checked={isChecked}
+        color={AvatarColors[0]}
+        conversationType="direct"
+        headerName={title}
+        i18n={i18n}
+        isMe={false}
+        isSelected={false}
+        isUsernameSearchResult
+        onClick={onClickItem}
+        shouldShowSpinner={isFetching}
+        theme={theme}
+        sharedGroupNames={[]}
+        title={title}
+      />
+    );
+  }
+);
diff --git a/ts/components/leftPane/LeftPaneChooseGroupMembersHelper.tsx b/ts/components/leftPane/LeftPaneChooseGroupMembersHelper.tsx
index 4dd4b9ee2..e6611d0e4 100644
--- a/ts/components/leftPane/LeftPaneChooseGroupMembersHelper.tsx
+++ b/ts/components/leftPane/LeftPaneChooseGroupMembersHelper.tsx
@@ -18,10 +18,14 @@ import {
 } from '../AddGroupMemberErrorDialog';
 import { Button } from '../Button';
 import type { LocalizerType } from '../../types/Util';
+import { getUsernameFromSearch } from '../../types/Username';
 import type { ParsedE164Type } from '../../util/libphonenumberInstance';
 import { parseAndFormatPhoneNumber } from '../../util/libphonenumberInstance';
 import type { UUIDFetchStateType } from '../../util/uuidFetchState';
-import { isFetchingByE164 } from '../../util/uuidFetchState';
+import {
+  isFetchingByUsername,
+  isFetchingByE164,
+} from '../../util/uuidFetchState';
 import {
   getGroupSizeRecommendedLimit,
   getGroupSizeHardLimit,
@@ -32,6 +36,7 @@ export type LeftPaneChooseGroupMembersPropsType = {
   candidateContacts: ReadonlyArray<ConversationType>;
   isShowingRecommendedGroupSizeModal: boolean;
   isShowingMaximumGroupSizeModal: boolean;
+  isUsernamesEnabled: boolean;
   searchTerm: string;
   regionCode: string | undefined;
   selectedContacts: Array<ConversationType>;
@@ -42,6 +47,8 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
 
   private readonly isPhoneNumberChecked: boolean;
 
+  private readonly isUsernameChecked: boolean;
+
   private readonly isShowingMaximumGroupSizeModal: boolean;
 
   private readonly isShowingRecommendedGroupSizeModal: boolean;
@@ -50,6 +57,8 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
 
   private readonly phoneNumber: ParsedE164Type | undefined;
 
+  private readonly username: string | undefined;
+
   private readonly selectedContacts: Array<ConversationType>;
 
   private readonly selectedConversationIdsSet: Set<string>;
@@ -60,6 +69,7 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
     candidateContacts,
     isShowingMaximumGroupSizeModal,
     isShowingRecommendedGroupSizeModal,
+    isUsernamesEnabled,
     searchTerm,
     regionCode,
     selectedContacts,
@@ -90,6 +100,22 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
     } else {
       this.isPhoneNumberChecked = false;
     }
+    if (!this.phoneNumber && isUsernamesEnabled) {
+      const username = getUsernameFromSearch(searchTerm);
+      const isVisible = this.candidateContacts.every(
+        contact => contact.username !== username
+      );
+
+      if (isVisible) {
+        this.username = username;
+      }
+
+      this.isUsernameChecked = selectedContacts.some(
+        contact => contact.username === this.username
+      );
+    } else {
+      this.isUsernameChecked = false;
+    }
     this.selectedContacts = selectedContacts;
 
     this.selectedConversationIdsSet = new Set(
@@ -246,6 +272,11 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
       rowCount += 2;
     }
 
+    // Header + Username
+    if (this.username) {
+      rowCount += 2;
+    }
+
     // Header + Contacts
     if (this.candidateContacts.length) {
       rowCount += 1 + this.candidateContacts.length;
@@ -260,7 +291,7 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
   }
 
   getRow(actualRowIndex: number): undefined | Row {
-    if (!this.candidateContacts.length && !this.phoneNumber) {
+    if (!this.candidateContacts.length && !this.phoneNumber && !this.username) {
       return undefined;
     }
 
@@ -322,6 +353,24 @@ export class LeftPaneChooseGroupMembersHelper extends LeftPaneHelper<LeftPaneCho
       virtualRowIndex -= 2;
     }
 
+    if (this.username) {
+      if (virtualRowIndex === 0) {
+        return {
+          type: RowType.Header,
+          i18nKey: 'findByUsernameHeader',
+        };
+      }
+      if (virtualRowIndex === 1) {
+        return {
+          type: RowType.UsernameCheckbox,
+          isChecked: this.isUsernameChecked,
+          isFetching: isFetchingByUsername(this.uuidFetchState, this.username),
+          username: this.username,
+        };
+      }
+      virtualRowIndex -= 2;
+    }
+
     return undefined;
   }
 
diff --git a/ts/components/leftPane/LeftPaneComposeHelper.tsx b/ts/components/leftPane/LeftPaneComposeHelper.tsx
index 49f47a103..884334027 100644
--- a/ts/components/leftPane/LeftPaneComposeHelper.tsx
+++ b/ts/components/leftPane/LeftPaneComposeHelper.tsx
@@ -43,14 +43,16 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
 
   private readonly uuidFetchState: UUIDFetchStateType;
 
-  private readonly isUsernamesEnabled: boolean;
-
   private readonly searchTerm: string;
 
   private readonly phoneNumber: ParsedE164Type | undefined;
 
   private readonly isPhoneNumberVisible: boolean;
 
+  private readonly username: string | undefined;
+
+  private readonly isUsernameVisible: boolean;
+
   constructor({
     composeContacts,
     composeGroups,
@@ -74,7 +76,18 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       this.isPhoneNumberVisible = false;
     }
     this.uuidFetchState = uuidFetchState;
-    this.isUsernamesEnabled = isUsernamesEnabled;
+
+    if (isUsernamesEnabled && !this.phoneNumber) {
+      this.username = getUsernameFromSearch(this.searchTerm);
+      this.isUsernameVisible =
+        isUsernamesEnabled &&
+        Boolean(this.username) &&
+        this.composeContacts.every(
+          contact => contact.username !== this.username
+        );
+    } else {
+      this.isUsernameVisible = false;
+    }
   }
 
   override getHeaderContents({
@@ -148,7 +161,7 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
     if (this.hasGroupsHeader()) {
       result += 1;
     }
-    if (this.getUsernameFromSearch()) {
+    if (this.isUsernameVisible) {
       result += 2;
     }
     if (this.isPhoneNumberVisible) {
@@ -218,8 +231,7 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       virtualRowIndex -= this.composeGroups.length;
     }
 
-    const username = this.getUsernameFromSearch();
-    if (username) {
+    if (this.username && this.isUsernameVisible) {
       if (virtualRowIndex === 0) {
         return {
           type: RowType.Header,
@@ -232,10 +244,10 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       if (virtualRowIndex === 0) {
         return {
           type: RowType.UsernameSearchResult,
-          username,
+          username: this.username,
           isFetchingUsername: isFetchingByUsername(
             this.uuidFetchState,
-            username
+            this.username
           ),
         };
 
@@ -295,7 +307,8 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       currHeaderIndices.top !== prevHeaderIndices.top ||
       currHeaderIndices.contact !== prevHeaderIndices.contact ||
       currHeaderIndices.group !== prevHeaderIndices.group ||
-      currHeaderIndices.username !== prevHeaderIndices.username
+      currHeaderIndices.username !== prevHeaderIndices.username ||
+      currHeaderIndices.phoneNumber !== prevHeaderIndices.phoneNumber
     );
   }
 
@@ -318,31 +331,17 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
     return Boolean(this.composeGroups.length);
   }
 
-  private getUsernameFromSearch(): string | undefined {
-    if (!this.isUsernamesEnabled) {
-      return undefined;
-    }
-
-    if (this.phoneNumber) {
-      return undefined;
-    }
-
-    if (this.searchTerm) {
-      return getUsernameFromSearch(this.searchTerm);
-    }
-
-    return undefined;
-  }
-
   private getHeaderIndices(): {
     top?: number;
     contact?: number;
     group?: number;
+    phoneNumber?: number;
     username?: number;
   } {
     let top: number | undefined;
     let contact: number | undefined;
     let group: number | undefined;
+    let phoneNumber: number | undefined;
     let username: number | undefined;
 
     let rowCount = 0;
@@ -359,7 +358,10 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       group = rowCount;
       rowCount += this.composeContacts.length;
     }
-    if (this.getUsernameFromSearch()) {
+    if (this.phoneNumber) {
+      phoneNumber = rowCount;
+    }
+    if (this.username) {
       username = rowCount;
     }
 
@@ -367,6 +369,7 @@ export class LeftPaneComposeHelper extends LeftPaneHelper<LeftPaneComposePropsTy
       top,
       contact,
       group,
+      phoneNumber,
       username,
     };
   }
diff --git a/ts/state/smart/ChooseGroupMembersModal.tsx b/ts/state/smart/ChooseGroupMembersModal.tsx
index 765e2a0ae..3cb62c460 100644
--- a/ts/state/smart/ChooseGroupMembersModal.tsx
+++ b/ts/state/smart/ChooseGroupMembersModal.tsx
@@ -12,6 +12,7 @@ import type { StatePropsType } from '../../components/conversation/conversation-
 import { ChooseGroupMembersModal } from '../../components/conversation/conversation-details/AddGroupMembersModal/ChooseGroupMembersModal';
 
 import { getIntl, getTheme, getRegionCode } from '../selectors/user';
+import { getUsernamesEnabled } from '../selectors/items';
 import {
   getCandidateContactsForNewGroup,
   getConversationByIdSelector,
@@ -55,6 +56,7 @@ const mapStateToProps = (
     theme: getTheme(state),
     selectedContacts,
     lookupConversationWithoutUuid,
+    isUsernamesEnabled: getUsernamesEnabled(state),
   };
 };
 
diff --git a/ts/state/smart/LeftPane.tsx b/ts/state/smart/LeftPane.tsx
index 1e4c26829..892642529 100644
--- a/ts/state/smart/LeftPane.tsx
+++ b/ts/state/smart/LeftPane.tsx
@@ -156,6 +156,7 @@ const getModeSpecificProps = (
         regionCode: getRegionCode(state),
         searchTerm: getComposerConversationSearchTerm(state),
         selectedContacts: getComposeSelectedContacts(state),
+        isUsernamesEnabled: getUsernamesEnabled(state),
         uuidFetchState: getComposerUUIDFetchState(state),
       };
     case ComposerStep.SetGroupMetadata:
diff --git a/ts/test-node/components/leftPane/LeftPaneChooseGroupMembersHelper_test.ts b/ts/test-node/components/leftPane/LeftPaneChooseGroupMembersHelper_test.ts
index 316173b1d..e107a4ccc 100644
--- a/ts/test-node/components/leftPane/LeftPaneChooseGroupMembersHelper_test.ts
+++ b/ts/test-node/components/leftPane/LeftPaneChooseGroupMembersHelper_test.ts
@@ -17,6 +17,7 @@ describe('LeftPaneChooseGroupMembersHelper', () => {
     candidateContacts: [],
     isShowingRecommendedGroupSizeModal: false,
     isShowingMaximumGroupSizeModal: false,
+    isUsernamesEnabled: true,
     searchTerm: '',
     regionCode: 'US',
     selectedContacts: [],
@@ -62,6 +63,7 @@ describe('LeftPaneChooseGroupMembersHelper', () => {
           candidateContacts: [],
           searchTerm: 'foo bar',
           selectedContacts: [getDefaultConversation()],
+          isUsernamesEnabled: false,
         }).getRowCount(),
         0
       );
@@ -107,6 +109,7 @@ describe('LeftPaneChooseGroupMembersHelper', () => {
           candidateContacts: [],
           searchTerm: 'foo bar',
           selectedContacts: [getDefaultConversation()],
+          isUsernamesEnabled: false,
         }).getRow(0)
       );
     });
@@ -120,6 +123,7 @@ describe('LeftPaneChooseGroupMembersHelper', () => {
         ...defaults,
         candidateContacts,
         searchTerm: 'foo bar',
+        isUsernamesEnabled: false,
         selectedContacts: [candidateContacts[1]],
       });
 
@@ -164,5 +168,51 @@ describe('LeftPaneChooseGroupMembersHelper', () => {
         disabledReason: undefined,
       });
     });
+
+    it('returns a header, then the phone number, then a blank space if there are contacts', () => {
+      const helper = new LeftPaneChooseGroupMembersHelper({
+        ...defaults,
+        candidateContacts: [],
+        searchTerm: '212 555',
+        selectedContacts: [],
+      });
+
+      assert.deepEqual(helper.getRow(0), {
+        type: RowType.Header,
+        i18nKey: 'findByPhoneNumberHeader',
+      });
+      assert.deepEqual(helper.getRow(1), {
+        type: RowType.PhoneNumberCheckbox,
+        phoneNumber: {
+          isValid: false,
+          userInput: '212 555',
+          e164: '+1212555',
+        },
+        isChecked: false,
+        isFetching: false,
+      });
+      assert.deepEqual(helper.getRow(2), { type: RowType.Blank });
+    });
+
+    it('returns a header, then the username, then a blank space if there are contacts', () => {
+      const helper = new LeftPaneChooseGroupMembersHelper({
+        ...defaults,
+        candidateContacts: [],
+        searchTerm: 'signal',
+        selectedContacts: [],
+      });
+
+      assert.deepEqual(helper.getRow(0), {
+        type: RowType.Header,
+        i18nKey: 'findByUsernameHeader',
+      });
+      assert.deepEqual(helper.getRow(1), {
+        type: RowType.UsernameCheckbox,
+        username: 'signal',
+        isChecked: false,
+        isFetching: false,
+      });
+      assert.deepEqual(helper.getRow(2), { type: RowType.Blank });
+    });
   });
 });
diff --git a/ts/textsecure/WebAPI.ts b/ts/textsecure/WebAPI.ts
index db800d99f..a966d143e 100644
--- a/ts/textsecure/WebAPI.ts
+++ b/ts/textsecure/WebAPI.ts
@@ -1626,7 +1626,7 @@ export function initialize({
       return (await _ajax({
         call: 'profile',
         httpType: 'GET',
-        urlParameters: `username/${usernameToFetch}`,
+        urlParameters: `/username/${usernameToFetch}`,
         responseType: 'json',
         redactUrl: _createRedactor(usernameToFetch),
       })) as ProfileType;