diff --git a/litellm/router_utils/reasoning_effort_capability.py b/litellm/router_utils/reasoning_effort_capability.py
index 2a4fae4109f..399f97a9864 100644
--- a/litellm/router_utils/reasoning_effort_capability.py
+++ b/litellm/router_utils/reasoning_effort_capability.py
@@ -148,16 +148,23 @@ def resolve_supported_reasoning_efforts(
     unset flag as () would let one custom deployment empty every level its mapped siblings agree
     on. deployment_is_mapped is that provenance, and an operator who wants either answer for an
     off-map deployment gets it by setting supports_reasoning explicitly.
+
+    If no explicit supports_reasoning flag is set but at least one per-level flag (e.g.
+    supports_minimal_reasoning_effort) is present, treat supports_reasoning as implicitly True,
+    since the per-level flags are evidence the model supports reasoning.
     """
     supports_reasoning: Final = model_info.get("supports_reasoning")
+    flags: Final = _declared_effort_flags(model_info)
+    has_per_level_flag: Final = any(value is not None for value in flags.values())
+
     if supports_reasoning is not True:
-        return () if supports_reasoning is False or deployment_is_mapped else None
+        if not has_per_level_flag:
+            return () if supports_reasoning is False or deployment_is_mapped else None
 
     declared: Final = declared_reasoning_efforts(model_info)
     if declared is not None:
         return declared
 
-    flags: Final = _declared_effort_flags(model_info)
     if all(value is None for value in flags.values()):
         return None
 
diff --git a/tests/test_litellm/router_utils/test_reasoning_effort_capability.py b/tests/test_litellm/router_utils/test_reasoning_effort_capability.py
index ff5660288f5..fd5926b75f0 100644
--- a/tests/test_litellm/router_utils/test_reasoning_effort_capability.py
+++ b/tests/test_litellm/router_utils/test_reasoning_effort_capability.py
@@ -85,6 +85,18 @@ class TestResolveSupportedReasoningEfforts:
         )
         assert resolved == ("none", "minimal", "low", "medium", "high")
 
+    def test_per_level_flag_without_supports_reasoning_treats_as_implicit_true(self):
+        # A model with only a per-level flag (e.g. supports_minimal_reasoning_effort) but no
+        # explicit supports_reasoning should be treated as reasoning-capable, since the per-level
+        # flag is evidence of reasoning support.
+        resolved = resolve_supported_reasoning_efforts(
+            {
+                "supports_minimal_reasoning_effort": True,
+            },
+            deployment_is_mapped=True,
+        )
+        assert resolved == ("none", "minimal", "low", "medium", "high")
+
 
 class TestBareModelNameFallback:
     def test_a_prefixed_entry_inherits_the_flags_of_its_unprefixed_twin(self):