diff --git a/lib/utils/url-utils.js b/lib/utils/url-utils.js
--- a/lib/utils/url-utils.js
+++ b/lib/utils/url-utils.js
@@ -13,6 +13,8 @@
   +apps?: boolean,
   +thread?: string,
   +settings?: 'account' | 'danger-zone',
+  +threadCreation?: boolean,
+  +selectedUserList?: $ReadOnlyArray<string>,
   ...
 };
 
@@ -31,6 +33,10 @@
   `(/|^)thread/(${locallyUniqueThreadIDRegex})(/|$)`,
   'i',
 );
+const threadCreationRegex = new RegExp(
+  '(/|^)thread/new(/([0-9+]*))?(/|$)',
+  'i',
+);
 
 function infoFromURL(url: string): URLInfo {
   const yearMatches = yearRegex.exec(url);
@@ -43,6 +49,7 @@
   const accountSettingsTest = accountSettingsRegex.test(url);
   const dangerZoneTest = dangerZoneRegex.test(url);
   const threadPendingMatches = threadPendingRegex.exec(url);
+  const threadCreateMatches = threadCreationRegex.exec(url);
 
   const returnObj = {};
   if (yearMatches) {
@@ -61,6 +68,10 @@
   if (threadPendingMatches) {
     returnObj.thread = threadPendingMatches[2];
   }
+  if (threadCreateMatches) {
+    returnObj.threadCreation = true;
+    returnObj.selectedUserList = threadCreateMatches[3]?.split('+') ?? [];
+  }
   if (verifyMatches) {
     returnObj.verify = verifyMatches[2];
   }
diff --git a/web/types/nav-types.js b/web/types/nav-types.js
--- a/web/types/nav-types.js
+++ b/web/types/nav-types.js
@@ -7,12 +7,16 @@
 
 export type NavigationSettingsSection = 'account' | 'danger-zone';
 
+export type NavigationChatMode = 'view' | 'create';
+
 export type NavInfo = {
   ...$Exact<BaseNavInfo>,
   +tab: NavigationTab,
   +activeChatThreadID: ?string,
   +pendingThread?: ThreadInfo,
   +settingsSection?: NavigationSettingsSection,
+  +selectedUserList?: $ReadOnlyArray<string>,
+  +chatMode?: NavigationChatMode,
 };
 
 export const updateNavInfoActionType = 'UPDATE_NAV_INFO';
diff --git a/web/url-utils.js b/web/url-utils.js
--- a/web/url-utils.js
+++ b/web/url-utils.js
@@ -54,9 +54,15 @@
         newURL += `month/${month}/`;
       }
     } else if (navInfo.tab === 'chat') {
-      const activeChatThreadID = navInfo.activeChatThreadID;
-      if (activeChatThreadID) {
-        newURL += `thread/${activeChatThreadID}/`;
+      if (navInfo.chatMode === 'create') {
+        const users = navInfo.selectedUserList?.join('+') ?? '';
+        const trailingSlash = users.length ? '/' : '';
+        newURL += `thread/new/${users}${trailingSlash}`;
+      } else {
+        const activeChatThreadID = navInfo.activeChatThreadID;
+        if (activeChatThreadID) {
+          newURL += `thread/${activeChatThreadID}/`;
+        }
       }
     } else if (navInfo.tab === 'settings' && navInfo.settingsSection) {
       newURL += `${navInfo.settingsSection}/`;
@@ -108,21 +114,28 @@
     tab = 'settings';
   }
 
-  const newNavInfo = {
+  let chatMode = 'view';
+  if (urlInfo.threadCreation) {
+    chatMode = 'create';
+  }
+
+  const newNavInfo: NavInfo = {
     tab,
     startDate: startDateForYearAndMonth(year, month),
     endDate: endDateForYearAndMonth(year, month),
     activeChatThreadID,
+    chatMode,
   };
 
-  if (!urlInfo.settings) {
-    return newNavInfo;
+  if (urlInfo.selectedUserList) {
+    newNavInfo.selectedUserList = urlInfo.selectedUserList;
   }
 
-  return {
-    ...newNavInfo,
-    settingsSection: urlInfo.settings,
-  };
+  if (urlInfo.settings) {
+    newNavInfo.settingsSection = urlInfo.settings;
+  }
+
+  return newNavInfo;
 }
 
 export { canonicalURLFromReduxState, navInfoFromURL };