diff --git a/alerting/src/main/kotlin/org/opensearch/alerting/TriggerService.kt b/alerting/src/main/kotlin/org/opensearch/alerting/TriggerService.kt
index 77ea886a8..282ebda59 100644
--- a/alerting/src/main/kotlin/org/opensearch/alerting/TriggerService.kt
+++ b/alerting/src/main/kotlin/org/opensearch/alerting/TriggerService.kt
@@ -125,9 +125,11 @@ class TriggerService(val scriptService: ScriptService) {
         val keyValuesList = mutableListOf<String>()
         when {
             bucket[keyField] is String -> keyValuesList.add(bucket[keyField] as String)
+            // In the case where the key field is an Int
+            bucket[keyField] is Int -> keyValuesList.add(bucket[keyField].toString())
             // In the case where the key field is an object with multiple values (such as a composite aggregation with more than one source)
             // the values will be iterated through and converted into a string
-            bucket[keyField] is Map<*, *> -> (bucket[keyField] as Map<String, Any>).values.map { keyValuesList.add(it as String) }
+            bucket[keyField] is Map<*, *> -> (bucket[keyField] as Map<String, Any>).values.map { keyValuesList.add(it.toString()) }
             else -> throw IllegalArgumentException("Unexpected format for key in bucket [$bucket]")
         }
 
diff --git a/alerting/src/test/kotlin/org/opensearch/alerting/TriggerServiceTests.kt b/alerting/src/test/kotlin/org/opensearch/alerting/TriggerServiceTests.kt
new file mode 100644
index 000000000..d4b7d63a4
--- /dev/null
+++ b/alerting/src/test/kotlin/org/opensearch/alerting/TriggerServiceTests.kt
@@ -0,0 +1,76 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.alerting
+
+import org.junit.Before
+import org.mockito.Mockito
+import org.opensearch.alerting.model.BucketLevelTriggerRunResult
+import org.opensearch.alerting.model.InputRunResults
+import org.opensearch.alerting.model.MonitorRunResult
+import org.opensearch.alerting.script.BucketLevelTriggerExecutionContext
+import org.opensearch.common.xcontent.DeprecationHandler
+import org.opensearch.common.xcontent.NamedXContentRegistry
+import org.opensearch.common.xcontent.XContentType
+import org.opensearch.script.ScriptService
+import org.opensearch.test.OpenSearchTestCase
+import java.time.Instant
+
+class TriggerServiceTests : OpenSearchTestCase() {
+    private lateinit var scriptService: ScriptService
+    private lateinit var triggerService: TriggerService
+
+    @Before
+    fun setup() {
+        scriptService = Mockito.mock(ScriptService::class.java)
+        triggerService = TriggerService(scriptService)
+    }
+
+    fun `test run bucket level trigger with bucket key as int`() {
+        val bucketSelectorExtAggregationBuilder = randomBucketSelectorExtAggregationBuilder(
+            bucketsPathsMap = mutableMapOf("_count" to "_count", "_key" to "_key"),
+            script = randomScript(source = "params._count > 0"),
+            parentBucketPath = "status_code"
+        )
+        val trigger = randomBucketLevelTrigger(bucketSelector = bucketSelectorExtAggregationBuilder)
+        val monitor = randomBucketLevelMonitor(triggers = listOf(trigger))
+
+        val inputResultsStr = "{\"_shards\":{\"total\":1,\"failed\":0,\"successful\":1,\"skipped\":0},\"hits\":{\"hits\":[{\"_index\":\"sample-http-responses\",\"_type\":\"http\",\"_source\":{\"status_code\":100,\"http_4xx\":0,\"http_3xx\":0,\"http_5xx\":0,\"http_2xx\":0,\"timestamp\":100000,\"http_1xx\":1},\"_id\":1,\"_score\":1}],\"total\":{\"value\":4,\"relation\":\"eq\"},\"max_score\":1},\"took\":37,\"timed_out\":false,\"aggregations\":{\"status_code\":{\"doc_count_error_upper_bound\":0,\"sum_other_doc_count\":0,\"buckets\":[{\"doc_count\":2,\"key\":100},{\"doc_count\":1,\"key\":102},{\"doc_count\":1,\"key\":201}]},\"${trigger.id}\":{\"parent_bucket_path\":\"status_code\",\"bucket_indices\":[0,1,2]}}}"
+
+        val parser = XContentType.JSON.xContent().createParser(NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, inputResultsStr)
+
+        val inputResults = parser.map()
+
+        var monitorRunResult = MonitorRunResult<BucketLevelTriggerRunResult>(monitor.name, Instant.now(), Instant.now())
+        monitorRunResult = monitorRunResult.copy(inputResults = InputRunResults(listOf(inputResults)))
+        val triggerCtx = BucketLevelTriggerExecutionContext(monitor, trigger, monitorRunResult)
+
+        val bucketLevelTriggerRunResult = triggerService.runBucketLevelTrigger(monitor, trigger, triggerCtx)
+        assertNull(bucketLevelTriggerRunResult.error)
+    }
+
+    fun `test run bucket level trigger with bucket key as map`() {
+        val bucketSelectorExtAggregationBuilder = randomBucketSelectorExtAggregationBuilder(
+            bucketsPathsMap = mutableMapOf("_count" to "_count", "_key" to "_key"),
+            script = randomScript(source = "params._count > 0"),
+            parentBucketPath = "status_code"
+        )
+        val trigger = randomBucketLevelTrigger(bucketSelector = bucketSelectorExtAggregationBuilder)
+        val monitor = randomBucketLevelMonitor(triggers = listOf(trigger))
+
+        val inputResultsStr = "{\"_shards\":{\"total\":1, \"failed\":0, \"successful\":1, \"skipped\":0}, \"hits\":{\"hits\":[{\"_index\":\"sample-http-responses\", \"_type\":\"http\", \"_source\":{\"status_code\":100, \"http_4xx\":0, \"http_3xx\":0, \"http_5xx\":0, \"http_2xx\":0, \"timestamp\":100000, \"http_1xx\":1}, \"_id\":1, \"_score\":1.0}, {\"_index\":\"sample-http-responses\", \"_type\":\"http\", \"_source\":{\"status_code\":102, \"http_4xx\":0, \"http_3xx\":0, \"http_5xx\":0, \"http_2xx\":0, \"timestamp\":160000, \"http_1xx\":1}, \"_id\":2, \"_score\":1.0}, {\"_index\":\"sample-http-responses\", \"_type\":\"http\", \"_source\":{\"status_code\":100, \"http_4xx\":0, \"http_3xx\":0, \"http_5xx\":0, \"http_2xx\":0, \"timestamp\":220000, \"http_1xx\":1}, \"_id\":4, \"_score\":1.0}, {\"_index\":\"sample-http-responses\", \"_type\":\"http\", \"_source\":{\"status_code\":201, \"http_4xx\":0, \"http_3xx\":0, \"http_5xx\":0, \"http_2xx\":1, \"timestamp\":280000, \"http_1xx\":0}, \"_id\":5, \"_score\":1.0}], \"total\":{\"value\":4, \"relation\":\"eq\"}, \"max_score\":1.0}, \"took\":15, \"timed_out\":false, \"aggregations\":{\"${trigger.id}\":{\"parent_bucket_path\":\"status_code\", \"bucket_indices\":[0, 1, 2]}, \"status_code\":{\"buckets\":[{\"doc_count\":2, \"key\":{\"status_code\":100}}, {\"doc_count\":1, \"key\":{\"status_code\":102}}, {\"doc_count\":1, \"key\":{\"status_code\":201}}], \"after_key\":{\"status_code\":201}}}}"
+
+        val parser = XContentType.JSON.xContent().createParser(NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, inputResultsStr)
+
+        val inputResults = parser.map()
+
+        var monitorRunResult = MonitorRunResult<BucketLevelTriggerRunResult>(monitor.name, Instant.now(), Instant.now())
+        monitorRunResult = monitorRunResult.copy(inputResults = InputRunResults(listOf(inputResults)))
+        val triggerCtx = BucketLevelTriggerExecutionContext(monitor, trigger, monitorRunResult)
+
+        val bucketLevelTriggerRunResult = triggerService.runBucketLevelTrigger(monitor, trigger, triggerCtx)
+        assertNull(bucketLevelTriggerRunResult.error)
+    }
+}