diff --git a/src/main/java/wanted/media/exception/ErrorCode.java b/src/main/java/wanted/media/exception/ErrorCode.java
index dd34485..b709326 100644
--- a/src/main/java/wanted/media/exception/ErrorCode.java
+++ b/src/main/java/wanted/media/exception/ErrorCode.java
@@ -10,7 +10,12 @@ public enum ErrorCode {
     ENTITY_NOT_FOUND(HttpStatus.NOT_FOUND, "존재하지 않는 엔티티입니다."),
     // 클라이언트의 입력 값에 대한 일반적인 오류 (@PathVariable, @RequestParam가 잘못되었을 때)
     INVALID_INPUT_VALUE(HttpStatus.BAD_REQUEST, "클라이언트의 입력 값을 확인해주세요."),
-  	INVALID_PARAMETER(HttpStatus.BAD_REQUEST, "잘못된 요청입니다.");
+  	INVALID_PARAMETER(HttpStatus.BAD_REQUEST, "잘못된 요청입니다."),
+
+    USER_NOT_FOUND(HttpStatus.NOT_FOUND, "사용자를 찾을 수 없습니다."),
+    INVALID_PASSWORD(HttpStatus.BAD_REQUEST, "비밀번호가 일치하지 않습니다."),
+    VERIFICATION_CODE_MISMATCH(HttpStatus.BAD_REQUEST, "인증코드가 일치하지 않습니다."),
+    VERIFICATION_CODE_EXPIRED(HttpStatus.BAD_REQUEST, "만료된 인증코드입니다.");
 
     private final HttpStatus status;
     private final String message;
diff --git a/src/main/java/wanted/media/exception/InvalidPasswordException.java b/src/main/java/wanted/media/exception/InvalidPasswordException.java
new file mode 100644
index 0000000..3ff8264
--- /dev/null
+++ b/src/main/java/wanted/media/exception/InvalidPasswordException.java
@@ -0,0 +1,8 @@
+package wanted.media.exception;
+
+public class InvalidPasswordException extends BaseException {
+    public InvalidPasswordException() {
+
+        super(ErrorCode.INVALID_PASSWORD);
+    }
+}
diff --git a/src/main/java/wanted/media/exception/UserNotFoundException.java b/src/main/java/wanted/media/exception/UserNotFoundException.java
new file mode 100644
index 0000000..5e8535d
--- /dev/null
+++ b/src/main/java/wanted/media/exception/UserNotFoundException.java
@@ -0,0 +1,7 @@
+package wanted.media.exception;
+
+public class UserNotFoundException extends BaseException {
+    public UserNotFoundException() {
+        super(ErrorCode.USER_NOT_FOUND);
+    }
+}
diff --git a/src/main/java/wanted/media/exception/VerificationCodeExpiredException.java b/src/main/java/wanted/media/exception/VerificationCodeExpiredException.java
new file mode 100644
index 0000000..6fd18c3
--- /dev/null
+++ b/src/main/java/wanted/media/exception/VerificationCodeExpiredException.java
@@ -0,0 +1,7 @@
+package wanted.media.exception;
+
+public class VerificationCodeExpiredException extends BaseException {
+    public VerificationCodeExpiredException() {
+        super(ErrorCode.VERIFICATION_CODE_EXPIRED);
+    }
+}
diff --git a/src/main/java/wanted/media/exception/VerificationCodeMismatchException.java b/src/main/java/wanted/media/exception/VerificationCodeMismatchException.java
new file mode 100644
index 0000000..d5f538d
--- /dev/null
+++ b/src/main/java/wanted/media/exception/VerificationCodeMismatchException.java
@@ -0,0 +1,7 @@
+package wanted.media.exception;
+
+public class VerificationCodeMismatchException extends BaseException {
+    public VerificationCodeMismatchException() {
+        super(ErrorCode.VERIFICATION_CODE_MISMATCH);
+    }
+}
diff --git a/src/main/java/wanted/media/exception/handler/GlobalExceptionHandler.java b/src/main/java/wanted/media/exception/handler/GlobalExceptionHandler.java
index 0ee7a8f..e2b74ce 100644
--- a/src/main/java/wanted/media/exception/handler/GlobalExceptionHandler.java
+++ b/src/main/java/wanted/media/exception/handler/GlobalExceptionHandler.java
@@ -5,8 +5,9 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
-import wanted.media.exception.CustomException;
+import wanted.media.exception.BaseException;
 import wanted.media.exception.ErrorCode;
+import wanted.media.exception.CustomException;
 import wanted.media.exception.ErrorResponse;
 import wanted.media.exception.NotFoundException;
 
@@ -18,7 +19,6 @@ public ResponseEntity<ErrorResponse> handleBadRequestException(BadRequestExcepti
         return ResponseEntity.badRequest()
                 .body(new ErrorResponse(400, e.getMessage()));
     }
-  
     @ExceptionHandler(NotFoundException.class)
     public ResponseEntity<ErrorResponse> handlePostNotFound(NotFoundException e) {
         ErrorCode errorCode = e.getErrorCode();
@@ -28,11 +28,16 @@ public ResponseEntity<ErrorResponse> handlePostNotFound(NotFoundException e) {
         );
         return ResponseEntity.status(HttpStatus.NOT_FOUND).body(errorResponse);
     }
-
     @ExceptionHandler(CustomException.class)
     protected ResponseEntity<ErrorResponse> handleCustomException(final CustomException e) {
         return ResponseEntity
                 .status(e.getErrorCode().getStatus().value())
                 .body(new ErrorResponse(e.getErrorCode().getStatus().value(), e.getCustomMessage()));
     }
+    @ExceptionHandler(BaseException.class)
+    public ResponseEntity<ErrorResponse> handleBaseException(BaseException e) {
+        ErrorCode errorCode = e.getErrorCode();
+        return ResponseEntity.status(errorCode.getStatus())
+                .body(new ErrorResponse(errorCode.getStatus().value(), errorCode.getMessage()));
+    }
 }
diff --git a/src/main/java/wanted/media/user/controller/UserController.java b/src/main/java/wanted/media/user/controller/UserController.java
index 1d649c4..d524408 100644
--- a/src/main/java/wanted/media/user/controller/UserController.java
+++ b/src/main/java/wanted/media/user/controller/UserController.java
@@ -10,8 +10,11 @@
 import org.springframework.web.bind.annotation.RestController;
 import wanted.media.user.dto.SignUpRequest;
 import wanted.media.user.dto.SignUpResponse;
+import wanted.media.user.dto.VerifyRequest;
+import wanted.media.user.dto.VerifyResponse;
 import wanted.media.user.dto.UserLoginRequestDto;
 import wanted.media.user.dto.UserLoginResponseDto;
+import wanted.media.user.dto.*;
 import wanted.media.user.service.UserService;
 
 @RestController
@@ -26,10 +29,27 @@ public ResponseEntity<UserLoginResponseDto> loginUser(@RequestBody UserLoginRequ
         return ResponseEntity.ok().body(responseDto);
     }
 
-    //회원가입
+    // 회원가입 API
     @PostMapping("/sign-up")
     public ResponseEntity<SignUpResponse> signUp(@Validated @RequestBody SignUpRequest request) {
         SignUpResponse response = userService.signUp(request);
         return ResponseEntity.status(HttpStatus.CREATED).body(response);
     }
+
+    /*
+     * 가입승인 API
+     * 회원등급 (normal -> premium)
+     * */
+    @PostMapping("/approve")
+    public ResponseEntity<VerifyResponse> approveSignUp(@RequestBody VerifyRequest request) {
+        VerifyResponse response = userService.approveSignUp(request);
+        return ResponseEntity.status(HttpStatus.CREATED).body(response);
+    }
+
+    // 인증코드 재발급 요청 API
+    @PostMapping("/reissue-code")
+    public ResponseEntity<ReissueCodeResponse> reissueCode(@RequestBody ReissueCodeRequest request) {
+        ReissueCodeResponse response = userService.reissueCode(request);
+        return ResponseEntity.status(HttpStatus.CREATED).body(response);
+    }
 }
diff --git a/src/main/java/wanted/media/user/domain/Code.java b/src/main/java/wanted/media/user/domain/Code.java
index c6167c8..2811fe4 100644
--- a/src/main/java/wanted/media/user/domain/Code.java
+++ b/src/main/java/wanted/media/user/domain/Code.java
@@ -19,7 +19,7 @@ public class Code {
     @Column(nullable = false)
     private Long codeId;
 
-    @OneToOne
+    @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "user_id")
     private User user;
 
diff --git a/src/main/java/wanted/media/user/dto/ReissueCodeRequest.java b/src/main/java/wanted/media/user/dto/ReissueCodeRequest.java
new file mode 100644
index 0000000..00b9911
--- /dev/null
+++ b/src/main/java/wanted/media/user/dto/ReissueCodeRequest.java
@@ -0,0 +1,4 @@
+package wanted.media.user.dto;
+
+public record ReissueCodeRequest(String account, String password) {
+}
diff --git a/src/main/java/wanted/media/user/dto/ReissueCodeResponse.java b/src/main/java/wanted/media/user/dto/ReissueCodeResponse.java
new file mode 100644
index 0000000..ace75df
--- /dev/null
+++ b/src/main/java/wanted/media/user/dto/ReissueCodeResponse.java
@@ -0,0 +1,4 @@
+package wanted.media.user.dto;
+
+public record ReissueCodeResponse(String message, String newAuthCode) {
+}
diff --git a/src/main/java/wanted/media/user/dto/UserInfoDto.java b/src/main/java/wanted/media/user/dto/UserInfoDto.java
new file mode 100644
index 0000000..c2899a4
--- /dev/null
+++ b/src/main/java/wanted/media/user/dto/UserInfoDto.java
@@ -0,0 +1,6 @@
+package wanted.media.user.dto;
+
+import wanted.media.user.domain.Grade;
+
+public record UserInfoDto(String account, String email, Grade grade) {
+}
\ No newline at end of file
diff --git a/src/main/java/wanted/media/user/dto/VerifyRequest.java b/src/main/java/wanted/media/user/dto/VerifyRequest.java
new file mode 100644
index 0000000..3d0b086
--- /dev/null
+++ b/src/main/java/wanted/media/user/dto/VerifyRequest.java
@@ -0,0 +1,11 @@
+package wanted.media.user.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+public record VerifyRequest(
+        @NotBlank @Size(max = 50) String account,
+        @NotBlank @Size(min = 10, max = 200, message = "비밀번호는 최소 10자리 이상으로 설정해주세요.") String password,
+        @NotBlank @Size(max = 10) String inputCode
+) {
+}
\ No newline at end of file
diff --git a/src/main/java/wanted/media/user/dto/VerifyResponse.java b/src/main/java/wanted/media/user/dto/VerifyResponse.java
new file mode 100644
index 0000000..57164b5
--- /dev/null
+++ b/src/main/java/wanted/media/user/dto/VerifyResponse.java
@@ -0,0 +1,4 @@
+package wanted.media.user.dto;
+
+public record VerifyResponse(String message, UserInfoDto dto) {
+}
\ No newline at end of file
diff --git a/src/main/java/wanted/media/user/repository/CodeRepository.java b/src/main/java/wanted/media/user/repository/CodeRepository.java
index d24c229..cede332 100644
--- a/src/main/java/wanted/media/user/repository/CodeRepository.java
+++ b/src/main/java/wanted/media/user/repository/CodeRepository.java
@@ -1,10 +1,23 @@
 package wanted.media.user.repository;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import wanted.media.user.domain.Code;
 import wanted.media.user.domain.User;
 
+import java.util.List;
+import java.util.Optional;
+
 public interface CodeRepository extends JpaRepository<Code, Long> {
-    // 사용자별 인증코드 중복확인
-    boolean existsByUserAndAuthCode(User user, String newAuthCode);
+    // 특정 사용자 인증코드로 조회
+    Optional<Code> findByUserAndAuthCode(User user, String authCode);
+
+    //사용자가 발급받은 인증코드 삭제
+    void deleteByUser(User user);
+
+    // 사용자에 대해 모든 인증 코드 조회
+    @Query("SELECT c FROM Code c WHERE c.user = :user ORDER BY c.createdTime DESC")
+    List<Code> findAllByUserOrderByCreatedTimeDesc(@Param("user") User user);
+
 }
diff --git a/src/main/java/wanted/media/user/repository/UserRepository.java b/src/main/java/wanted/media/user/repository/UserRepository.java
index f48d108..3cff36c 100644
--- a/src/main/java/wanted/media/user/repository/UserRepository.java
+++ b/src/main/java/wanted/media/user/repository/UserRepository.java
@@ -1,6 +1,10 @@
 package wanted.media.user.repository;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import wanted.media.user.domain.Grade;
 import wanted.media.user.domain.User;
 
 import java.util.Optional;
@@ -12,4 +16,9 @@ public interface UserRepository extends JpaRepository<User, UUID> {
 
     // 사용자 이메일로 회원 조회
     Optional<User> findByEmail(String email);
+
+    // 가입인증 회원 등급 변경
+    @Modifying
+    @Query("UPDATE User u SET u.grade = :grade WHERE u.account = :account")
+    void updateUserGrade(@Param("account") String account, @Param("grade") Grade grade);
 }
diff --git a/src/main/java/wanted/media/user/service/UserService.java b/src/main/java/wanted/media/user/service/UserService.java
index 49da7b8..3ab0392 100644
--- a/src/main/java/wanted/media/user/service/UserService.java
+++ b/src/main/java/wanted/media/user/service/UserService.java
@@ -1,10 +1,14 @@
 package wanted.media.user.service;
 
+import jakarta.transaction.Transactional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
 import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Transactional;
 import wanted.media.user.config.TokenProvider;
+import wanted.media.exception.InvalidPasswordException;
+import wanted.media.exception.UserNotFoundException;
+import wanted.media.exception.VerificationCodeExpiredException;
+import wanted.media.exception.VerificationCodeMismatchException;
 import wanted.media.user.domain.Code;
 import wanted.media.user.domain.Grade;
 import wanted.media.user.domain.Token;
@@ -16,6 +20,7 @@
 
 import java.time.LocalDateTime;
 import java.util.Optional;
+import java.util.List;
 
 @Service
 @RequiredArgsConstructor
@@ -29,7 +34,7 @@ public class UserService {
     private final UserValidator userValidator;
     private final GenerateCode generateCode;
 
-    @Transactional
+
     public UserLoginResponseDto login(UserLoginRequestDto requestDto) {
         User user = userRepository.findByAccount(requestDto.getAccount())
                 .orElseThrow(() -> new IllegalArgumentException("account나 password를 다시 확인해주세요."));
@@ -77,4 +82,57 @@ public SignUpResponse signUp(SignUpRequest request) {
         // 9. SignUpResponse 생성 및 반환
         return new SignUpResponse("회원가입이 완료되었습니다.", userCreateDto, verificationCode);
     }
+
+    //가입승인
+    public VerifyResponse approveSignUp(VerifyRequest verifyRequest) {
+        // 1. account로 사용자 조회
+        User user = userRepository.findByAccount(verifyRequest.account())
+                .orElseThrow(UserNotFoundException::new);
+        // 2. 비밀번호 검증
+        if (!passwordEncoder.matches(verifyRequest.password(), user.getPassword())) {
+            throw new InvalidPasswordException();
+        }
+        // 3. 사용자 인증코드 검증
+        Code code = codeRepository.findByUserAndAuthCode(user, verifyRequest.inputCode())
+                .orElseThrow(VerificationCodeMismatchException::new);
+        // 4. 해당 사용자의 모든 인증코드 조회 (최신순 정렬)
+        List<Code> userCodes = codeRepository.findAllByUserOrderByCreatedTimeDesc(user);
+        // 5. 해당 사용자에게 발급된 모든 인증코드와 입력된 인증코드 일치 조회
+        if (!userCodes.isEmpty() && !userCodes.get(0).equals(code)) {
+            throw new VerificationCodeMismatchException();
+        }
+        // 6. 인증코드 유효성 검증 (유효시간 15분)
+        if (code.getCreatedTime().plusMinutes(15).isBefore(LocalDateTime.now())) {
+            throw new VerificationCodeExpiredException();
+        }
+        // 7. 인증 완료 -> 회원 등급 변경 (normal -> premium)
+        userRepository.updateUserGrade(user.getAccount(), Grade.PREMIUM_USER);
+        // 8. 인증 완료 회원 인증코드 삭제
+        codeRepository.deleteByUser(user);
+        return new VerifyResponse("인증이 성공적으로 완료되었습니다!",
+                new UserInfoDto(user.getAccount(), user.getEmail(), user.getGrade()));
+    }
+
+    // 인증코드 재발급
+    public ReissueCodeResponse reissueCode(ReissueCodeRequest reissueCodeRequest) {
+        // 1. account로 사용자 조회
+        User user = userRepository.findByAccount(reissueCodeRequest.account())
+                .orElseThrow(UserNotFoundException::new);
+        // 2. 비밀번호 검증
+        if (!passwordEncoder.matches(reissueCodeRequest.password(), user.getPassword())) {
+            throw new InvalidPasswordException();
+        }
+        // 3. 새로운 인증코드 발급
+        String newAuthCode = generateCode.codeGenerate();
+        // 4. 코드 객체 생성
+        Code newCode = Code.builder()
+                .user(user)
+                .authCode(newAuthCode)
+                .createdTime(LocalDateTime.now())
+                .build();
+        // 5. 코드 db 저장
+        codeRepository.save(newCode);
+
+        return new ReissueCodeResponse("인증코드가 성공적으로 재발급되었습니다.", newAuthCode);
+    }
 }