diff --git a/src/fastmcp/server/auth/providers/bearer.py b/src/fastmcp/server/auth/providers/bearer.py
index 6ffffa909..c6e9024bc 100644
--- a/src/fastmcp/server/auth/providers/bearer.py
+++ b/src/fastmcp/server/auth/providers/bearer.py
@@ -24,6 +24,7 @@ from fastmcp.server.auth.auth import (
     OAuthProvider,
     RevocationOptions,
 )
+from fastmcp.utilities.logging import get_logger
 
 
 class JWKData(TypedDict, total=False):
@@ -199,6 +200,7 @@ class BearerAuthProvider(OAuthProvider):
         self.public_key = public_key
         self.jwks_uri = jwks_uri
         self.jwt = JsonWebToken(["RS256"])
+        self.logger = get_logger(__name__)
 
         # Simple JWKS cache
         self._jwks_cache: dict[str, str] = {}
@@ -265,6 +267,9 @@ class BearerAuthProvider(OAuthProvider):
             # Select the appropriate key
             if kid:
                 if kid not in self._jwks_cache:
+                    self.logger.debug(
+                        "JWKS key lookup failed: key ID '%s' not found", kid
+                    )
                     raise ValueError(f"Key ID '{kid}' not found in JWKS")
                 return self._jwks_cache[kid]
             else:
@@ -279,6 +284,7 @@ class BearerAuthProvider(OAuthProvider):
                     raise ValueError("No keys found in JWKS")
 
         except Exception as e:
+            self.logger.debug("JWKS fetch failed: %s", str(e))
             raise ValueError(f"Failed to fetch JWKS: {e}")
 
     async def load_access_token(self, token: str) -> AccessToken | None:
@@ -298,15 +304,27 @@ class BearerAuthProvider(OAuthProvider):
             # Decode and verify the JWT token
             claims = self.jwt.decode(token, verification_key)
 
+            # Extract client ID early for logging
+            client_id = claims.get("client_id") or claims.get("sub") or "unknown"
+
             # Validate expiration
             exp = claims.get("exp")
             if exp and exp < time.time():
+                self.logger.debug(
+                    "Token validation failed: expired token for client %s", client_id
+                )
+                self.logger.info("Bearer token rejected for client %s", client_id)
                 return None
 
             # Validate issuer - note we use issuer instead of issuer_url here because
             # issuer is optional, allowing users to make this check optional
             if self.issuer:
                 if claims.get("iss") != self.issuer:
+                    self.logger.debug(
+                        "Token validation failed: issuer mismatch for client %s",
+                        client_id,
+                    )
+                    self.logger.info("Bearer token rejected for client %s", client_id)
                     return None
 
             # Validate audience if configured
@@ -314,26 +332,33 @@ class BearerAuthProvider(OAuthProvider):
                 aud = claims.get("aud")
 
                 # Handle different combinations of audience types
+                audience_valid = False
                 if isinstance(self.audience, list):
                     # self.audience is a list - check if any expected audience is present
                     if isinstance(aud, list):
                         # Both are lists - check for intersection
-                        if not any(expected in aud for expected in self.audience):
-                            return None
+                        audience_valid = any(
+                            expected in aud for expected in self.audience
+                        )
                     else:
                         # aud is a string - check if it's in our expected list
-                        if aud not in self.audience:
-                            return None
+                        audience_valid = aud in self.audience
                 else:
                     # self.audience is a string - use original logic
                     if isinstance(aud, list):
-                        if self.audience not in aud:
-                            return None
-                    elif aud != self.audience:
-                        return None
+                        audience_valid = self.audience in aud
+                    else:
+                        audience_valid = aud == self.audience
 
-            # Extract claims - prefer client_id over sub for OAuth application identification
-            client_id = claims.get("client_id") or claims.get("sub") or "unknown"
+                if not audience_valid:
+                    self.logger.debug(
+                        "Token validation failed: audience mismatch for client %s",
+                        client_id,
+                    )
+                    self.logger.info("Bearer token rejected for client %s", client_id)
+                    return None
+
+            # Extract scopes
             scopes = self._extract_scopes(claims)
 
             return AccessToken(
@@ -344,8 +369,10 @@ class BearerAuthProvider(OAuthProvider):
             )
 
         except JoseError:
+            self.logger.debug("Token validation failed: JWT signature/format invalid")
             return None
-        except Exception:
+        except Exception as e:
+            self.logger.debug("Token validation failed: %s", str(e))
             return None
 
     def _extract_scopes(self, claims: dict[str, Any]) -> list[str]: