diff --git a/api/strategies/openIdJwtStrategy.js b/api/strategies/openIdJwtStrategy.js
index cc90e20036..841b645936 100644
--- a/api/strategies/openIdJwtStrategy.js
+++ b/api/strategies/openIdJwtStrategy.js
@@ -1,10 +1,11 @@
-const { SystemRoles } = require('librechat-data-provider');
-const { HttpsProxyAgent } = require('https-proxy-agent');
-const { Strategy: JwtStrategy, ExtractJwt } = require('passport-jwt');
-const { updateUser, findUser } = require('~/models');
-const { logger } = require('~/config');
 const jwksRsa = require('jwks-rsa');
-const { isEnabled } = require('~/server/utils');
+const { logger } = require('@librechat/data-schemas');
+const { HttpsProxyAgent } = require('https-proxy-agent');
+const { SystemRoles } = require('librechat-data-provider');
+const { Strategy: JwtStrategy, ExtractJwt } = require('passport-jwt');
+const { isEnabled, findOpenIDUser } = require('@librechat/api');
+const { updateUser, findUser } = require('~/models');
+
 /**
  * @function openIdJwtLogin
  * @param {import('openid-client').Configuration} openIdConfig - Configuration object for the JWT strategy.
@@ -13,6 +14,14 @@ const { isEnabled } = require('~/server/utils');
  * It uses the jwks-rsa library to retrieve the signing key from a JWKS endpoint.
  * The strategy extracts the JWT from the Authorization header as a Bearer token.
  * The JWT is then verified using the signing key, and the user is retrieved from the database.
+ *
+ * Includes email fallback mechanism:
+ * 1. Primary lookup: Search user by openidId (sub claim)
+ * 2. Fallback lookup: If not found, search by email claim
+ * 3. User migration: If found by email without openidId, migrate the user by adding openidId
+ * 4. Provider validation: Ensures users registered with other providers cannot use OpenID
+ *
+ * This enables seamless migration for existing users when SharePoint integration is enabled.
  */
 const openIdJwtLogin = (openIdConfig) => {
   let jwksRsaOptions = {
@@ -34,19 +43,41 @@ const openIdJwtLogin = (openIdConfig) => {
     },
     async (payload, done) => {
       try {
-        const user = await findUser({ openidId: payload?.sub });
+        const { user, error, migration } = await findOpenIDUser({
+          openidId: payload?.sub,
+          email: payload?.email,
+          strategyName: 'openIdJwtLogin',
+          findUser,
+        });
+
+        if (error) {
+          done(null, false, { message: error });
+          return;
+        }
 
         if (user) {
           user.id = user._id.toString();
+
+          const updateData = {};
+          if (migration) {
+            updateData.provider = 'openid';
+            updateData.openidId = payload?.sub;
+          }
           if (!user.role) {
             user.role = SystemRoles.USER;
-            await updateUser(user.id, { role: user.role });
+            updateData.role = user.role;
           }
+
+          if (Object.keys(updateData).length > 0) {
+            await updateUser(user.id, updateData);
+          }
+
           done(null, user);
         } else {
           logger.warn(
             '[openIdJwtLogin] openId JwtStrategy => no user found with the sub claims: ' +
-              payload?.sub,
+              payload?.sub +
+              (payload?.email ? ' or email: ' + payload.email : ''),
           );
           done(null, false);
         }
diff --git a/api/strategies/openidStrategy.js b/api/strategies/openidStrategy.js
index 4cb7493284..1116cbdc45 100644
--- a/api/strategies/openidStrategy.js
+++ b/api/strategies/openidStrategy.js
@@ -7,7 +7,13 @@ const { HttpsProxyAgent } = require('https-proxy-agent');
 const { hashToken, logger } = require('@librechat/data-schemas');
 const { CacheKeys, ErrorTypes } = require('librechat-data-provider');
 const { Strategy: OpenIDStrategy } = require('openid-client/passport');
-const { isEnabled, logHeaders, safeStringify, getBalanceConfig } = require('@librechat/api');
+const {
+  isEnabled,
+  logHeaders,
+  safeStringify,
+  findOpenIDUser,
+  getBalanceConfig,
+} = require('@librechat/api');
 const { getStrategyFunctions } = require('~/server/services/Files/strategies');
 const { findUser, createUser, updateUser } = require('~/models');
 const { getAppConfig } = require('~/server/services/Config');
@@ -333,23 +339,16 @@ async function setupOpenId() {
       async (tokenset, done) => {
         try {
           const claims = tokenset.claims();
-          let user = await findUser({ openidId: claims.sub });
-          logger.info(
-            `[openidStrategy] user ${user ? 'found' : 'not found'} with openidId: ${claims.sub}`,
-          );
+          const result = await findOpenIDUser({
+            openidId: claims.sub,
+            email: claims.email,
+            strategyName: 'openidStrategy',
+            findUser,
+          });
+          let user = result.user;
+          const error = result.error;
 
-          if (!user) {
-            user = await findUser({ email: claims.email });
-            logger.info(
-              `[openidStrategy] user ${user ? 'found' : 'not found'} with email: ${
-                claims.email
-              } for openidId: ${claims.sub}`,
-            );
-          }
-          if (user != null && user.provider !== 'openid') {
-            logger.info(
-              `[openidStrategy] Attempted OpenID login by user ${user.email}, was registered with "${user.provider}" provider`,
-            );
+          if (error) {
             return done(null, false, {
               message: ErrorTypes.AUTH_FAILED,
             });
diff --git a/api/strategies/openidStrategy.spec.js b/api/strategies/openidStrategy.spec.js
index 5bbf194f45..de033b01f8 100644
--- a/api/strategies/openidStrategy.spec.js
+++ b/api/strategies/openidStrategy.spec.js
@@ -31,6 +31,7 @@ jest.mock('@librechat/data-schemas', () => ({
   ...jest.requireActual('@librechat/api'),
   logger: {
     info: jest.fn(),
+    warn: jest.fn(),
     debug: jest.fn(),
     error: jest.fn(),
   },
diff --git a/packages/api/src/auth/index.ts b/packages/api/src/auth/index.ts
new file mode 100644
index 0000000000..a5fb25405a
--- /dev/null
+++ b/packages/api/src/auth/index.ts
@@ -0,0 +1 @@
+export * from './openid';
diff --git a/packages/api/src/auth/openid.ts b/packages/api/src/auth/openid.ts
new file mode 100644
index 0000000000..2b1d978c86
--- /dev/null
+++ b/packages/api/src/auth/openid.ts
@@ -0,0 +1,49 @@
+import { logger } from '@librechat/data-schemas';
+import type { IUser, UserMethods } from '@librechat/data-schemas';
+
+/**
+ * Finds or migrates a user for OpenID authentication
+ * @returns user object (with migration fields if needed), error message, and whether migration is needed
+ */
+export async function findOpenIDUser({
+  openidId,
+  email,
+  findUser,
+  strategyName = 'openid',
+}: {
+  openidId: string;
+  findUser: UserMethods['findUser'];
+  email?: string;
+  strategyName?: string;
+}): Promise<{ user: IUser | null; error: string | null; migration: boolean }> {
+  let user = await findUser({ openidId });
+  logger.info(`[${strategyName}] user ${user ? 'found' : 'not found'} with openidId: ${openidId}`);
+
+  // If user not found by openidId, try to find by email
+  if (!user && email) {
+    user = await findUser({ email });
+    logger.warn(
+      `[${strategyName}] user ${user ? 'found' : 'not found'} with email: ${email} for openidId: ${openidId}`,
+    );
+
+    // If user found by email, check if they're allowed to use OpenID provider
+    if (user && user.provider && user.provider !== 'openid') {
+      logger.warn(
+        `[${strategyName}] Attempted OpenID login by user ${user.email}, was registered with "${user.provider}" provider`,
+      );
+      return { user: null, error: 'AUTH_FAILED', migration: false };
+    }
+
+    // If user found by email but doesn't have openidId, prepare for migration
+    if (user && !user.openidId) {
+      logger.info(
+        `[${strategyName}] Preparing user ${user.email} for migration to OpenID with sub: ${openidId}`,
+      );
+      user.provider = 'openid';
+      user.openidId = openidId;
+      return { user, error: null, migration: true };
+    }
+  }
+
+  return { user, error: null, migration: false };
+}
diff --git a/packages/api/src/index.ts b/packages/api/src/index.ts
index 3fd81fa531..d0c797abaf 100644
--- a/packages/api/src/index.ts
+++ b/packages/api/src/index.ts
@@ -1,4 +1,6 @@
 export * from './app';
+/* Auth */
+export * from './auth';
 /* MCP */
 export * from './mcp/MCPManager';
 export * from './mcp/connection';