diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/MergeRecord.java b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/MergeRecord.java
index 727f384e6a..68519f2356 100644
--- a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/MergeRecord.java
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/MergeRecord.java
@@ -96,6 +96,9 @@ import java.util.stream.Collectors;
     @WritesAttribute(attribute = "merge.bin.age", description = "The age of the bin, in milliseconds, when it was merged and output. Effectively "
         + "this is the greatest amount of time that any FlowFile in this bundle remained waiting in this processor before it was output"),
     @WritesAttribute(attribute = "merge.uuid", description = "UUID of the merged FlowFile that will be added to the original FlowFiles attributes"),
+    @WritesAttribute(attribute = MergeRecord.MERGE_COMPLETION_REASON, description = "This processor allows for several thresholds to be configured for merging FlowFiles. "
+        + " This attribute indicates which of the Thresholds resulted in the FlowFiles being merged. For an explanation of each of the possible values "
+        + " and their meanings, see the Processor's Usage / documentation and see the 'Additional Details' page."),
     @WritesAttribute(attribute = "<Attributes from Record Writer>", description = "Any Attribute that the configured Record Writer returns will be added to the FlowFile.")
 })
 @SeeAlso({MergeContent.class, SplitRecord.class, PartitionRecord.class})
@@ -171,6 +174,7 @@ public class MergeRecord extends AbstractSessionFactoryProcessor {
     public static final String MERGE_COUNT_ATTRIBUTE = "merge.count";
     public static final String MERGE_BIN_AGE_ATTRIBUTE = "merge.bin.age";
     public static final String MERGE_UUID_ATTRIBUTE = "merge.uuid";
+    public static final String MERGE_COMPLETION_REASON = "merge.completion.reason";
 
     public static final AllowableValue MERGE_STRATEGY_BIN_PACK = new AllowableValue(
         "Bin-Packing Algorithm",
diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/merge/RecordBin.java b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/merge/RecordBin.java
index ebb6bdca7f..8b0553fb63 100644
--- a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/merge/RecordBin.java
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/merge/RecordBin.java
@@ -398,6 +398,7 @@ public class RecordBin {
             attributes.put(CoreAttributes.MIME_TYPE.key(), recordWriter.getMimeType());
             attributes.put(MergeRecord.MERGE_COUNT_ATTRIBUTE, Integer.toString(flowFiles.size()));
             attributes.put(MergeRecord.MERGE_BIN_AGE_ATTRIBUTE, Long.toString(getBinAge()));
+            attributes.put(MergeRecord.MERGE_COMPLETION_REASON, completionReason);
 
             merged = session.putAllAttributes(merged, attributes);
             flowFiles.forEach(ff -> session.putAttribute(ff, MergeRecord.MERGE_UUID_ATTRIBUTE, merged.getAttribute(CoreAttributes.UUID.key())));
diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestMergeRecord.java b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestMergeRecord.java
index dea9990f24..656b4d5af2 100644
--- a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestMergeRecord.java
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestMergeRecord.java
@@ -79,6 +79,7 @@ public class TestMergeRecord {
 
         runner.getFlowFilesForRelationship(MergeRecord.REL_ORIGINAL).forEach(
             ff -> assertEquals(mff.getAttribute(CoreAttributes.UUID.key()), ff.getAttribute(MergeRecord.MERGE_UUID_ATTRIBUTE)));
+        mff.assertAttributeEquals(MergeRecord.MERGE_COMPLETION_REASON, "Bin is full");
     }
 
     @Test
@@ -96,6 +97,7 @@ public class TestMergeRecord {
 
         runner.getFlowFilesForRelationship(MergeRecord.REL_ORIGINAL).forEach(
                 ff -> assertEquals(mff.getAttribute(CoreAttributes.UUID.key()), ff.getAttribute(MergeRecord.MERGE_UUID_ATTRIBUTE)));
+        mff.assertAttributeEquals(MergeRecord.MERGE_COMPLETION_REASON, "Bin is full enough");
     }
 
     @Test