diff --git a/src/KubernetesClient/KubernetesJson.cs b/src/KubernetesClient/KubernetesJson.cs
index 69ecdf43e..35cfe3acb 100644
--- a/src/KubernetesClient/KubernetesJson.cs
+++ b/src/KubernetesClient/KubernetesJson.cs
@@ -60,12 +60,20 @@ public override void Write(Utf8JsonWriter writer, DateTimeOffset value, JsonSeri
                 // Output as RFC3339Micro
                 var date = value.ToUniversalTime();
 
-                var basePart = date.ToString("yyyy-MM-dd'T'HH:mm:ss", CultureInfo.InvariantCulture);
-                var frac = date.ToString(".ffffff", CultureInfo.InvariantCulture)
-                    .TrimEnd('0')
-                    .TrimEnd('.');
-
-                writer.WriteStringValue(basePart + frac + "Z");
+                // Check if there are any fractional seconds
+                var ticks = date.Ticks % TimeSpan.TicksPerSecond;
+                if (ticks == 0)
+                {
+                    // No fractional seconds - use format without fractional part
+                    var basePart = date.ToString("yyyy-MM-dd'T'HH:mm:ss", CultureInfo.InvariantCulture);
+                    writer.WriteStringValue(basePart + "Z");
+                }
+                else
+                {
+                    // Has fractional seconds - always use exactly 6 decimal places
+                    var formatted = date.ToString(RFC3339MicroFormat, CultureInfo.InvariantCulture);
+                    writer.WriteStringValue(formatted);
+                }
             }
         }
 
diff --git a/tests/KubernetesClient.Tests/KubernetesJsonTests.cs b/tests/KubernetesClient.Tests/KubernetesJsonTests.cs
index 785e38fea..e8f199456 100644
--- a/tests/KubernetesClient.Tests/KubernetesJsonTests.cs
+++ b/tests/KubernetesClient.Tests/KubernetesJsonTests.cs
@@ -142,4 +142,31 @@ public void ReadWriteDatesJson()
 
         Assert.Equal(kManifest, jsonFromObj2);
     }
+
+    [Fact]
+    public void DateTimeWithFractionalSecondsAlwaysHasSixDigits()
+    {
+        // Test that datetime fields with fractional seconds always output exactly 6 decimal places
+        // This is required by Kubernetes API which expects RFC3339Micro format
+
+        // Create a datetime with 5 digits of precision (962170 microseconds = .96217 seconds)
+        var dt = new DateTime(2025, 11, 17, 22, 52, 34, 962, DateTimeKind.Utc).AddTicks(1700);
+
+        var secret = new V1Secret
+        {
+            Metadata = new V1ObjectMeta
+            {
+                Name = "test-secret",
+                CreationTimestamp = dt,
+            },
+        };
+
+        var json = KubernetesJson.Serialize(secret);
+
+        // Verify the datetime is serialized with exactly 6 decimal places
+        Assert.Contains("2025-11-17T22:52:34.962170Z", json);
+
+        // Also verify it doesn't have 5 digits (which would fail in Kubernetes)
+        Assert.DoesNotContain("2025-11-17T22:52:34.96217Z", json);
+    }
 }