diff --git a/src/NATS.Server/JetStream/Cluster/JetStreamMetaGroup.cs b/src/NATS.Server/JetStream/Cluster/JetStreamMetaGroup.cs
index 0a20dee..1f1c214 100644
--- a/src/NATS.Server/JetStream/Cluster/JetStreamMetaGroup.cs
+++ b/src/NATS.Server/JetStream/Cluster/JetStreamMetaGroup.cs
@@ -649,9 +649,32 @@ public sealed class JetStreamMetaGroup
         };
     }
 
+    /// <summary>
+    /// Fired when leadership changes. Argument is true when becoming leader, false when stepping down.
+    /// Go reference: jetstream_cluster.go processLeaderChange callback.
+    /// </summary>
+    public event Action<bool>? OnLeaderChange;
+
+    /// <summary>
+    /// Processes a leadership change event.
+    /// When stepping down: clears all inflight proposals.
+    /// When becoming leader: fires OnLeaderChange event.
+    /// Go reference: jetstream_cluster.go:7001-7074 processLeaderChange.
+    /// </summary>
+    public void ProcessLeaderChange(bool isLeader)
+    {
+        if (!isLeader)
+        {
+            // Stepping down — clear inflight
+            ClearAllInflight();
+        }
+
+        OnLeaderChange?.Invoke(isLeader);
+    }
+
     /// <summary>
     /// Steps down the current leader, rotating to the next node.
-    /// Clears all inflight proposals on leader change.
+    /// Clears all inflight proposals on leader change via ProcessLeaderChange.
     /// Go reference: jetstream_cluster.go leader stepdown, clear inflight.
     /// </summary>
     public void StepDown()
@@ -662,10 +685,7 @@ public sealed class JetStreamMetaGroup
 
         Interlocked.Increment(ref _leadershipVersion);
 
-        // Clear inflight on leader change
-        // Go reference: jetstream_cluster.go -- inflight entries are cleared when leadership changes.
-        _inflightStreams.Clear();
-        _inflightConsumers.Clear();
+        ProcessLeaderChange(isLeader: false);
     }
 
     // ---------------------------------------------------------------
diff --git a/tests/NATS.Server.Tests/JetStream/Cluster/JetStreamLeadershipTests.cs b/tests/NATS.Server.Tests/JetStream/Cluster/JetStreamLeadershipTests.cs
new file mode 100644
index 0000000..9e9ab16
--- /dev/null
+++ b/tests/NATS.Server.Tests/JetStream/Cluster/JetStreamLeadershipTests.cs
@@ -0,0 +1,97 @@
+using NATS.Server.JetStream.Cluster;
+
+namespace NATS.Server.Tests.JetStream.Cluster;
+
+public class JetStreamLeadershipTests
+{
+    [Fact]
+    public void ProcessLeaderChange_clears_inflight_on_step_down()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        meta.TrackInflightStreamProposal("ACC", new StreamAssignment
+        {
+            StreamName = "s1",
+            Group = new RaftGroup { Name = "rg", Peers = ["n1", "n2", "n3"] },
+        });
+
+        meta.ProcessLeaderChange(isLeader: false);
+
+        meta.InflightStreamCount.ShouldBe(0);
+    }
+
+    [Fact]
+    public void ProcessLeaderChange_fires_event_on_become_leader()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        var leaderChanged = false;
+        meta.OnLeaderChange += (isLeader) => leaderChanged = true;
+
+        meta.ProcessLeaderChange(isLeader: true);
+
+        leaderChanged.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void ProcessLeaderChange_fires_event_on_step_down()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        bool? receivedIsLeader = null;
+        meta.OnLeaderChange += (isLeader) => receivedIsLeader = isLeader;
+
+        meta.ProcessLeaderChange(isLeader: false);
+
+        receivedIsLeader.ShouldNotBeNull();
+        receivedIsLeader.Value.ShouldBeFalse();
+    }
+
+    [Fact]
+    public void StepDown_triggers_leader_change_event()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        bool? receivedIsLeader = null;
+        meta.OnLeaderChange += (isLeader) => receivedIsLeader = isLeader;
+
+        meta.StepDown();
+
+        receivedIsLeader.ShouldNotBeNull();
+        receivedIsLeader.Value.ShouldBeFalse();
+    }
+
+    [Fact]
+    public void StepDown_clears_inflight_via_process_leader_change()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        meta.TrackInflightStreamProposal("ACC", new StreamAssignment
+        {
+            StreamName = "s1",
+            Group = new RaftGroup { Name = "rg", Peers = ["n1", "n2", "n3"] },
+        });
+        meta.TrackInflightConsumerProposal("ACC", "s1", "c1");
+
+        meta.StepDown();
+
+        meta.InflightStreamCount.ShouldBe(0);
+        meta.InflightConsumerCount.ShouldBe(0);
+    }
+
+    [Fact]
+    public void BecomeLeader_makes_IsLeader_true()
+    {
+        var meta = new JetStreamMetaGroup(3);
+        meta.StepDown(); // move leader away from self
+        meta.IsLeader().ShouldBeFalse();
+
+        meta.BecomeLeader();
+
+        meta.IsLeader().ShouldBeTrue();
+    }
+
+    [Fact]
+    public void OnLeaderChange_not_fired_when_no_subscribers()
+    {
+        // Should not throw when no handlers attached
+        var meta = new JetStreamMetaGroup(3);
+        Should.NotThrow(() => meta.ProcessLeaderChange(isLeader: true));
+        Should.NotThrow(() => meta.ProcessLeaderChange(isLeader: false));
+    }
+}