diff --git a/src/main/java/com/promsearch/user/application/service/command/UserCommandService.java b/src/main/java/com/promsearch/user/application/service/command/UserCommandService.java
index 2d84116..f403b3c 100644
--- a/src/main/java/com/promsearch/user/application/service/command/UserCommandService.java
+++ b/src/main/java/com/promsearch/user/application/service/command/UserCommandService.java
@@ -26,11 +26,13 @@
 import com.promsearch.user.domain.InterestTagSelectionPolicy;
 import com.promsearch.user.domain.NicknamePolicy;
 import com.promsearch.user.domain.enums.InterestTagType;
+import com.promsearch.user.domain.enums.UserRole;
 import com.promsearch.user.domain.exception.UserDomainException;
 import com.promsearch.user.domain.exception.UserErrorCode;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
 import lombok.RequiredArgsConstructor;
@@ -170,8 +172,10 @@ public void bootstrap(BootstrapAdminAccountCommand command) {
             log.warn("admin_bootstrap_skipped reason=missing_config");
             return;
         }
-        if (loadUserPort.existsByEmail(command.email())) {
-            log.info("admin_bootstrap_skipped reason=already_exists email={}", command.email());
+
+        Optional<User> existingUser = loadUserPort.findByEmail(command.email());
+        if (existingUser.isPresent()) {
+            promoteToAdminIfNeeded(existingUser.get());
             return;
         }
 
@@ -181,6 +185,16 @@ public void bootstrap(BootstrapAdminAccountCommand command) {
         log.info("admin_bootstrap_completed userId={}", savedAdmin.getUserId().id());
     }
 
+    private void promoteToAdminIfNeeded(User user) {
+        if (user.getRole() == UserRole.ADMIN) {
+            log.info("admin_bootstrap_skipped reason=already_admin email={}", user.getEmail());
+            return;
+        }
+
+        User promotedAdmin = saveUserPort.update(user.promoteToAdmin());
+        log.info("admin_bootstrap_promoted userId={}", promotedAdmin.getUserId().id());
+    }
+
     private boolean isBlank(String value) {
         return value == null || value.isBlank();
     }
diff --git a/src/main/java/com/promsearch/user/domain/User.java b/src/main/java/com/promsearch/user/domain/User.java
index 7f30945..09fcbbf 100644
--- a/src/main/java/com/promsearch/user/domain/User.java
+++ b/src/main/java/com/promsearch/user/domain/User.java
@@ -257,6 +257,30 @@ public User promoteToOrigin() {
                 .build();
     }
 
+    /**
+     * 관리자 권한으로 승급한다. 배포 환경의 관리자 부트스트랩 계정이 일반 가입으로
+     * 먼저 생성돼 있던 경우, 재기동 시 이 메서드로 role을 맞춘다.
+     *
+     * @return ADMIN 권한으로 변경된 새 사용자 객체
+     */
+    public User promoteToAdmin() {
+        return User.builder()
+                .userId(userId)
+                .email(email)
+                .password(password)
+                .nickname(nickname)
+                .name(name)
+                .profileImageUrl(profileImageUrl)
+                .profileImageObjectKey(profileImageObjectKey)
+                .point(point)
+                .role(UserRole.ADMIN)
+                .grade(grade)
+                .status(status)
+                .createdAt(createdAt)
+                .updatedAt(Instant.now())
+                .build();
+    }
+
     public User changePassword(String password) {
         validateRequired(email, password, nickname, point, role, grade, status);
 
diff --git a/src/test/java/com/promsearch/user/application/service/command/UserCommandServiceTest.java b/src/test/java/com/promsearch/user/application/service/command/UserCommandServiceTest.java
index 8da3ca1..cb5e210 100644
--- a/src/test/java/com/promsearch/user/application/service/command/UserCommandServiceTest.java
+++ b/src/test/java/com/promsearch/user/application/service/command/UserCommandServiceTest.java
@@ -218,11 +218,38 @@ void bootstrapCreatesAdminAccountWhenNotExists() {
     }
 
     @Test
-    void bootstrapSkipsWhenAdminAlreadyExists() {
+    void bootstrapPromotesExistingUserToAdminWhenRoleIsNotAdmin() {
         userRepository.save(testUser(1L, "admin@example.com", "old-password", "admin", "admin", null, UserStatus.ACTIVE));
 
         userCommandService.bootstrap(BootstrapAdminAccountCommand.of("admin@example.com", "Admin1234!", "admin"));
 
+        assertThat(userRepository.users).hasSize(1);
+        User promoted = userRepository.users.get(1L);
+        assertThat(promoted.getRole()).isEqualTo(UserRole.ADMIN);
+        assertThat(promoted.getPassword()).isEqualTo("old-password");
+    }
+
+    @Test
+    void bootstrapSkipsWhenAdminAlreadyExistsWithAdminRole() {
+        User existingAdmin = User.reconstruct(
+                new UserId(1L),
+                "admin@example.com",
+                "old-password",
+                "admin",
+                "admin",
+                null,
+                null,
+                0L,
+                UserRole.ADMIN,
+                UserGrade.NODE,
+                UserStatus.ACTIVE,
+                Instant.now(),
+                Instant.now()
+        );
+        userRepository.save(existingAdmin);
+
+        userCommandService.bootstrap(BootstrapAdminAccountCommand.of("admin@example.com", "Admin1234!", "admin"));
+
         assertThat(userRepository.users).hasSize(1);
         assertThat(userRepository.users.get(1L).getPassword()).isEqualTo("old-password");
     }