diff --git a/changelog/2026-05-13-merge-queue-testing-duration-chart.mdx b/changelog/2026-05-13-merge-queue-testing-duration-chart.mdx
new file mode 100644
index 0000000..84016af
--- /dev/null
+++ b/changelog/2026-05-13-merge-queue-testing-duration-chart.mdx
@@ -0,0 +1,19 @@
+---
+title: "Merge Queue: Testing Duration Chart"
+description: "Track how long PRs spend in the testing phase of the merge queue, then drill into individual test runs."
+date: 2026-05-13
+category: Merge Queue
+type: new-feature
+---
+
+**The Merge Queue Health tab now has a Testing Duration chart that shows how long PRs spend in the testing phase**, separate from Time in Queue, which measures total entry-to-exit time. This isolates CI execution time from queue wait time, so you can tell whether a slow queue is a testing problem or a scheduling one.
+
+Each data point is one testing-to-final-state transition, so a PR appears more than once if its cycle restarted. The chart buckets and filters its data independently from the Conclusion count and Time in queue charts, so it does not share their hover sync.
+
+- **Outcome filter:** Passed, Failed, Interrupted, Cancelled
+- **Cycle ended in filter:** Merged, Failed, Cancelled, In Flight
+- **Statistical measures:** Average, Min, Max, Sum, P50, P95, P99
+
+Click a data point on the chart and an inline table appears below it, breaking out the individual test runs behind that period so you can spot slow or outlier runs without leaving the page.
+
+[Read the docs](https://docs.trunk.io/merge-queue/administration/metrics) to learn more.
diff --git a/changelog/index.mdx b/changelog/index.mdx
index 05e887d..9827e4d 100644
--- a/changelog/index.mdx
+++ b/changelog/index.mdx
@@ -50,6 +50,12 @@ rss: true
   Tag, organize, and filter your test suite with org-wide labels.
 </Update>
 
+<Update label="May 13, 2026" tags={["Merge Queue"]}>
+  **[Merge Queue: Testing Duration Chart](/changelog/2026-05-13-merge-queue-testing-duration-chart)**
+
+  Track how long PRs spend in the testing phase of the merge queue, then drill into individual test runs.
+</Update>
+
 ### April 2026
 
 <Update label="April 30, 2026" tags={["Merge Queue"]}>
diff --git a/docs.json b/docs.json
index 763b83c..07a3a8f 100644
--- a/docs.json
+++ b/docs.json
@@ -622,6 +622,7 @@
               "changelog/2026-05-18-flaky-tests-failure-count-monitor",
               "changelog/2026-05-18-flaky-tests-monitor-label-actions",
               "changelog/2026-05-18-flaky-tests-test-labels",
+              "changelog/2026-05-13-merge-queue-testing-duration-chart",
               "changelog/2026-04-30-merge-queue-chrome-extension",
               "changelog/2026-04-21-merge-queue-drill-down-into-merge-metrics",
               "changelog/2026-04-13-merge-queue-terraform-provider",
diff --git a/merge-queue/changelog.mdx b/merge-queue/changelog.mdx
index dd0518d..9e252e3 100644
--- a/merge-queue/changelog.mdx
+++ b/merge-queue/changelog.mdx
@@ -20,6 +20,12 @@ rss: true
   Apply a configured GitHub label to a PR to send it straight to the merge queue.
 </Update>
 
+<Update label="May 13, 2026" tags={["Merge Queue"]}>
+  **[Merge Queue: Testing Duration Chart](/changelog/2026-05-13-merge-queue-testing-duration-chart)**
+
+  Track how long PRs spend in the testing phase of the merge queue, then drill into individual test runs.
+</Update>
+
 ### April 2026
 
 <Update label="April 30, 2026" tags={["Merge Queue"]}>