diff --git a/CLAUDE.md b/CLAUDE.md
index 34bd686..4abdddb 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -553,3 +553,76 @@ const params = new URLSearchParams({
 **QSO Management**:
 - Fixed DELETE /api/qsos/all to handle foreign key constraints
 - Added cache invalidation after QSO deletion
+
+### Admin System and User Roles
+
+The application supports three user roles with different permission levels:
+
+**User Roles**:
+- **Regular User**: View own QSOs, sync from LoTW/DCL, track award progress
+- **Admin**: All user permissions + view system stats + manage users + impersonate regular users
+- **Super Admin**: All admin permissions + promote/demote admins + impersonate admins
+
+**Database Schema** (`src/backend/db/schema/index.js`):
+- `isAdmin`: Boolean flag for admin users (default: false)
+- `isSuperAdmin`: Boolean flag for super-admin users (default: false)
+
+**Admin Service** (`src/backend/services/admin.service.js`):
+- `isAdmin(userId)`: Check if user is admin
+- `isSuperAdmin(userId)`: Check if user is super-admin
+- `changeUserRole(adminId, targetUserId, newRole)`: Change user role ('user', 'admin', 'super-admin')
+- `impersonateUser(adminId, targetUserId)`: Start impersonating a user
+- `verifyImpersonation(token)`: Verify impersonation token validity
+- `stopImpersonation(adminId, targetUserId)`: Stop impersonation
+- `logAdminAction(adminId, actionType, targetUserId, details)`: Log admin actions
+
+**Security Rules**:
+1. Only super-admins can promote/demote super-admins
+2. Regular admins cannot promote users to super-admin
+3. Super-admins cannot demote themselves (prevents lockout)
+4. Cannot demote the last super-admin
+5. Regular admins can only impersonate regular users
+6. Super-admins can impersonate any user (including other admins)
+
+**Backend API Routes** (`src/backend/index.js`):
+- `POST /api/admin/users/:userId/role`: Change user role
+  - Body: `{ "role": "user" | "admin" | "super-admin" }`
+- `POST /api/admin/impersonate/:userId`: Start impersonating
+- `POST /api/admin/impersonate/stop`: Stop impersonating
+- `GET /api/admin/impersonation/status`: Check impersonation status
+- `GET /api/admin/stats`: System statistics
+- `GET /api/admin/users`: List all users
+- `GET /api/admin/actions`: Admin action log
+- `DELETE /api/admin/users/:userId`: Delete user
+
+**JWT Token Claims**:
+```javascript
+{
+  userId: number,
+  email: string,
+  callsign: string,
+  isAdmin: boolean,
+  isSuperAdmin: boolean,  // Super-admin flag
+  impersonatedBy: number,  // Present when impersonating
+  exp: number
+}
+```
+
+**Frontend Admin Page** (`src/frontend/src/routes/admin/+page.svelte`):
+- System statistics dashboard
+- User management with filtering (all, super-admin, admin, user)
+- Role change modal (user → admin → super-admin)
+- Impersonate button (enabled for super-admins targeting admins)
+- Admin action log viewing
+
+**To create the first super-admin**:
+1. Register a user account
+2. Access database: `sqlite3 src/backend/award.db`
+3. Run: `UPDATE users SET is_super_admin = 1 WHERE email = 'your@email.com';`
+4. Log out and log back in to get updated JWT token
+
+**To promote via admin interface**:
+1. Log in as existing super-admin
+2. Navigate to `/admin`
+3. Find user in Users tab
+4. Click "Promote" and select "Super Admin"
diff --git a/README.md b/README.md
index 6843f1f..d6e498e 100644
--- a/README.md
+++ b/README.md
@@ -277,6 +277,52 @@ The application will be available at:
 ### Health
 - `GET /api/health` - Health check endpoint
 
+### Admin API (Admin Only)
+
+All admin endpoints require authentication and admin privileges.
+
+- `GET /api/admin/stats` - Get system-wide statistics
+- `GET /api/admin/users` - Get all users with statistics
+- `GET /api/admin/users/:userId` - Get detailed information about a specific user
+- `POST /api/admin/users/:userId/role` - Update user role (`user`, `admin`, `super-admin`)
+- `DELETE /api/admin/users/:userId` - Delete a user
+- `POST /api/admin/impersonate/:userId` - Start impersonating a user
+- `POST /api/admin/impersonate/stop` - Stop impersonating and return to admin account
+- `GET /api/admin/impersonation/status` - Get current impersonation status
+- `GET /api/admin/actions` - Get admin actions log
+- `GET /api/admin/actions/my` - Get current admin's action log
+
+### User Roles and Permissions
+
+The application supports three user roles with different permission levels:
+
+**Regular User**
+- View own QSOs
+- Sync from LoTW and DCL
+- Track award progress
+- Manage own credentials
+
+**Admin**
+- All user permissions
+- View system statistics
+- View all users
+- Promote/demote regular users to/from admin
+- Delete regular users
+- Impersonate regular users (for support)
+- View admin action log
+
+**Super Admin**
+- All admin permissions
+- Promote/demote admins to/from super-admin
+- Impersonate other admins (for support)
+- Full access to all admin functions
+
+**Security Rules:**
+- Only super-admins can promote or demote super-admins
+- Regular admins cannot promote users to super-admin
+- Super-admins cannot demote themselves
+- Cannot demote the last super-admin
+
 ## Database Schema
 
 ### Users Table
@@ -289,6 +335,9 @@ CREATE TABLE users (
   lotwUsername TEXT,
   lotwPassword TEXT,
   dclApiKey TEXT,              -- DCL API key (for future use)
+  isAdmin INTEGER DEFAULT 0 NOT NULL,
+  isSuperAdmin INTEGER DEFAULT 0 NOT NULL,
+  lastSeen INTEGER,
   createdAt TEXT NOT NULL,
   updatedAt TEXT NOT NULL
 );
diff --git a/docs/DOCUMENTATION.md b/docs/DOCUMENTATION.md
index fd08486..52242eb 100644
--- a/docs/DOCUMENTATION.md
+++ b/docs/DOCUMENTATION.md
@@ -276,6 +276,9 @@ award/
   callsign: text (not null)
   lotwUsername: text (nullable)
   lotwPassword: text (nullable, encrypted)
+  isAdmin: boolean (default: false)
+  isSuperAdmin: boolean (default: false)
+  lastSeen: timestamp (nullable)
   createdAt: timestamp
   updatedAt: timestamp
 }
@@ -1034,7 +1037,197 @@ When adding new awards or modifying the award system:
 
 ---
 
-## Resources
+## Admin System
+
+### Overview
+
+The admin system provides user management, role-based access control, and account impersonation capabilities for support and administrative purposes.
+
+### User Roles
+
+The application supports three user roles with increasing permissions:
+
+#### Regular User
+- View own QSOs and statistics
+- Sync from LoTW and DCL
+- Track award progress
+- Manage own credentials (LoTW, DCL)
+
+#### Admin
+- All user permissions
+- View system-wide statistics
+- View all users and their activity
+- Promote/demote regular users to/from admin role
+- Delete regular users
+- Impersonate regular users (for support)
+- View admin action log
+
+#### Super Admin
+- All admin permissions
+- Promote/demote admins to/from super-admin role
+- Impersonate other admins (for support)
+- Cannot be demoted by regular admins
+- Protected from accidental lockout
+
+### Security Rules
+
+**Role Change Restrictions:**
+- Only super-admins can promote or demote super-admins
+- Regular admins cannot promote users to super-admin
+- Super-admins cannot demote themselves
+- Cannot demote the last super-admin (prevents lockout)
+
+**Impersonation Restrictions:**
+- Regular admins can only impersonate regular users
+- Super-admins can impersonate any user (including other admins)
+- All impersonation actions are logged to audit trail
+- Impersonation tokens expire after 1 hour
+
+### Admin API Endpoints
+
+**Statistics and Monitoring:**
+- `GET /api/admin/stats` - System-wide statistics (users, QSOs, jobs)
+- `GET /api/admin/users` - List all users with statistics
+- `GET /api/admin/users/:userId` - Get detailed user information
+- `GET /api/admin/actions` - View admin action log
+- `GET /api/admin/actions/my` - View current admin's actions
+
+**User Management:**
+- `POST /api/admin/users/:userId/role` - Change user role
+  - Body: `{ "role": "user" | "admin" | "super-admin" }`
+- `DELETE /api/admin/users/:userId` - Delete a user
+
+**Impersonation:**
+- `POST /api/admin/impersonate/:userId` - Start impersonating a user
+- `POST /api/admin/impersonate/stop` - Stop impersonation
+- `GET /api/admin/impersonation/status` - Check impersonation status
+
+### Admin Service
+
+**File:** `src/backend/services/admin.service.js`
+
+**Key Functions:**
+
+```javascript
+// Check user permissions
+await isAdmin(userId)
+await isSuperAdmin(userId)
+
+// Role management
+await changeUserRole(adminId, targetUserId, newRole)
+
+// Impersonation
+await impersonateUser(adminId, targetUserId)
+await verifyImpersonation(impersonationToken)
+await stopImpersonation(adminId, targetUserId)
+
+// Audit logging
+await logAdminAction(adminId, actionType, targetUserId, details)
+```
+
+### Audit Logging
+
+All admin actions are logged to the `admin_actions` table for audit purposes:
+
+**Action Types:**
+- `impersonate_start` - Started impersonating a user
+- `impersonate_stop` - Stopped impersonation
+- `role_change` - Changed user role
+- `user_delete` - Deleted a user
+
+**Log Entry Structure:**
+```javascript
+{
+  id: integer,
+  adminId: integer,
+  actionType: string,
+  targetUserId: integer (nullable),
+  details: string (JSON),
+  createdAt: timestamp
+}
+```
+
+### Frontend Admin Interface
+
+**Route:** `/admin` (admin only)
+
+**Features:**
+- **Overview Tab:** System statistics dashboard
+- **Users Tab:** User management with filtering
+- **Awards Tab:** Award definition management
+- **Action Log Tab:** Audit trail of admin actions
+
+**User Management Actions:**
+- **Impersonate** - Switch to user account (disabled for admins unless super-admin)
+- **Promote/Demote** - Change user role
+- **Delete** - Remove user and all associated data
+
+### JWT Token Claims
+
+Admin tokens include additional claims:
+
+```javascript
+{
+  userId: number,
+  email: string,
+  callsign: string,
+  isAdmin: boolean,
+  isSuperAdmin: boolean,  // New: Super-admin flag
+  exp: number
+}
+```
+
+**Impersonation Token:**
+```javascript
+{
+  userId: number,           // Target user ID
+  email: string,
+  callsign: string,
+  isAdmin: boolean,
+  isSuperAdmin: boolean,
+  impersonatedBy: number,   // Admin ID who started impersonation
+  exp: number               // 1 hour expiration
+}
+```
+
+### Setup
+
+**To create the first super-admin:**
+
+1. Register a user account normally
+2. Access the database directly:
+```bash
+sqlite3 src/backend/award.db
+```
+
+3. Update the user to super-admin:
+```sql
+UPDATE users SET is_super_admin = 1 WHERE email = 'your@email.com';
+```
+
+4. Log out and log back in to get the updated JWT token
+
+**To promote users via the admin interface:**
+1. Log in as a super-admin
+2. Navigate to `/admin`
+3. Find the user in the Users tab
+4. Click "Promote" and select "Super Admin"
+
+### Production Deployment
+
+After pulling the latest code:
+
+```bash
+# Apply database migration (adds is_super_admin column)
+sqlite3 src/backend/award.db "ALTER TABLE users ADD COLUMN is_super_admin INTEGER DEFAULT 0 NOT NULL;"
+
+# Restart backend
+pm2 restart award-backend
+
+# Promote a user to super-admin via database or existing admin interface
+```
+
+---
 
 - [ARRL LoTW](https://lotw.arrl.org/)
 - [DARC Community Logbook (DCL)](https://dcl.darc.de/)