diff --git a/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/JsonCounterLogger.cs b/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/JsonCounterLogger.cs
index fd4d9ab511f..7e0eb3b68f5 100644
--- a/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/JsonCounterLogger.cs
+++ b/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/JsonCounterLogger.cs
@@ -47,22 +47,22 @@ protected override async Task SerializeAsync(ICounterPayload counter)
                 return;
             }
 
-            if (counter is PercentilePayload percentilePayload)
+            if (counter is AggregatePercentilePayload aggregatePercentilePayload)
             {
-                if (!percentilePayload.Quantiles.Any())
+                if (!aggregatePercentilePayload.Quantiles.Any())
                 {
                     return;
                 }
                 await _stream.WriteAsync(JsonSequenceRecordSeparator);
                 _bufferWriter.Clear();
 
-                for (int i = 0; i < percentilePayload.Quantiles.Length; i++)
+                for (int i = 0; i < aggregatePercentilePayload.Quantiles.Length; i++)
                 {
                     if (i > 0)
                     {
                         _bufferWriter.Write(JsonSequenceRecordSeparator.Span);
                     }
-                    Quantile quantile = percentilePayload.Quantiles[i];
+                    Quantile quantile = aggregatePercentilePayload.Quantiles[i];
 
                     SerializeCounterValues(counter.Timestamp,
                         counter.Provider,
@@ -73,7 +73,7 @@ protected override async Task SerializeAsync(ICounterPayload counter)
                         CounterUtilities.AppendPercentile(counter.Metadata, quantile.Percentage),
                         quantile.Value);
 
-                    if (i < percentilePayload.Quantiles.Length - 1)
+                    if (i < aggregatePercentilePayload.Quantiles.Length - 1)
                     {
                         _bufferWriter.Write(NewLineSeparator.Span);
                     }
diff --git a/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/MetricsStore.cs b/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/MetricsStore.cs
index acb0ca8bebe..5a3f6b03f5f 100644
--- a/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/MetricsStore.cs
+++ b/src/Microsoft.Diagnostics.Monitoring.WebApi/Metrics/MetricsStore.cs
@@ -64,7 +64,7 @@ public MetricsStore(ILogger<MetricsStoreService> logger, int maxMetricCount)
 
         public void AddMetric(ICounterPayload metric)
         {
-            if (metric is PercentilePayload payload && !payload.Quantiles.Any())
+            if (metric is AggregatePercentilePayload payload && !payload.Quantiles.Any())
             {
                 // If histogram data is not generated in the monitored app, we can get Histogram events that do not contain quantiles.
                 // For now, we will ignore these events.
@@ -106,7 +106,7 @@ public void AddMetric(ICounterPayload metric)
                 }
 
                 // CONSIDER We only keep 1 histogram representation per snapshot. Is it meaningful for Prometheus to see previous histograms? These are not timestamped.
-                if ((metrics.Count > 1) && (metric is PercentilePayload))
+                if ((metrics.Count > 1) && (metric is AggregatePercentilePayload))
                 {
                     metrics.Dequeue();
                 }
@@ -138,10 +138,10 @@ public async Task SnapshotMetrics(Stream outputStream, CancellationToken token)
 
                 foreach (var metric in metricGroup.Value)
                 {
-                    if (metric is PercentilePayload percentilePayload)
+                    if (metric is AggregatePercentilePayload aggregatePayload)
                     {
                         // Summary quantiles must appear from smallest to largest
-                        foreach (Quantile quantile in percentilePayload.Quantiles.OrderBy(q => q.Percentage))
+                        foreach (Quantile quantile in aggregatePayload.Quantiles.OrderBy(q => q.Percentage))
                         {
                             string metricValue = PrometheusDataModel.GetPrometheusNormalizedValue(metric.Unit, quantile.Value);
                             string metricLabels = GetMetricLabels(metric, quantile.Percentage);
@@ -226,7 +226,7 @@ private static async Task WriteMetricDetails(
                 await writer.WriteAsync("{" + metricLabels + "}");
             }
 
-            string lineSuffix = metric is PercentilePayload ? string.Empty : FormattableString.Invariant($" {new DateTimeOffset(metric.Timestamp).ToUnixTimeMilliseconds()}");
+            string lineSuffix = metric is AggregatePercentilePayload ? string.Empty : FormattableString.Invariant($" {new DateTimeOffset(metric.Timestamp).ToUnixTimeMilliseconds()}");
 
             await writer.WriteLineAsync(FormattableString.Invariant($" {metricValue}{lineSuffix}"));
         }
diff --git a/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.FunctionalTests/LiveMetricsTests.cs b/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.FunctionalTests/LiveMetricsTests.cs
index 4b9ca161d72..393530c7c49 100644
--- a/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.FunctionalTests/LiveMetricsTests.cs
+++ b/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.FunctionalTests/LiveMetricsTests.cs
@@ -187,7 +187,9 @@ await ScenarioRunner.SingleTarget(
                     // will fail and will need to be updated.
                     Regex regex = new Regex(@"\bPercentile=(50|95|99)");
 
-                    for (int index = 0; index < actualMeterNames.Count; ++index)
+                    int startingIndex = instrumentNamesP1.Length + instrumentNamesP2.Length; // Accounts for empty InstrumentStarted payloads
+
+                    for (int index = startingIndex; index < actualMeterNames.Count; ++index)
                     {
                         if (actualInstrumentNames[index] == Constants.HistogramName1)
                         {
diff --git a/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/MetricsFormattingTests.cs b/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/MetricsFormattingTests.cs
index 85cdf0febd3..4bbcc8972c9 100644
--- a/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/MetricsFormattingTests.cs
+++ b/src/Tests/Microsoft.Diagnostics.Monitoring.Tool.UnitTests/MetricsFormattingTests.cs
@@ -44,8 +44,8 @@ public async Task HistogramFormat_Test()
         {
             List<ICounterPayload> payload = new();
 
-            payload.Add(new PercentilePayload(MeterName, InstrumentName, "DisplayName", string.Empty, string.Empty,
-                new Quantile[] { new(0.5, Value1), new(0.95, Value2), new(0.99, Value3) },
+            payload.Add(new AggregatePercentilePayload(MeterName, InstrumentName, "DisplayName", string.Empty, string.Empty,
+                new Quantile[] { new Quantile(0.5, Value1), new Quantile(0.95, Value2), new Quantile(0.99, Value3) },
                 Timestamp));
 
             using MemoryStream stream = await GetMetrics(payload);