diff --git a/create/src/schema.tmpl b/create/src/schema.tmpl
index d8427b6a3a8..dcbed0c5edf 100644
--- a/create/src/schema.tmpl
+++ b/create/src/schema.tmpl
@@ -2000,6 +2000,7 @@ FIELD		|effective_date	|t_integer	|'0'	|NOT NULL	|0
 FIELD		|timezone	|t_varchar(50)	|'UTC'	|NOT NULL	|ZBX_NODATA
 FIELD		|status		|t_integer	|'1'	|NOT NULL	|0
 FIELD		|description	|t_text		|''	|NOT NULL	|0
+FIELD		|og_min_down_severity	|t_integer	|'0'	|NOT NULL	|0
 UNIQUE		|1		|name
 
 TABLE|sla_schedule|sla_scheduleid|ZBX_DATA
diff --git a/ui/app/controllers/CControllerSlaCreate.php b/ui/app/controllers/CControllerSlaCreate.php
index 42b58c46933..adc85c5d1ac 100644
--- a/ui/app/controllers/CControllerSlaCreate.php
+++ b/ui/app/controllers/CControllerSlaCreate.php
@@ -38,6 +38,7 @@ class CControllerSlaCreate extends CControllerSlaCreateUpdate {
 			'service_tags' =>		'required|array',
 			'description' =>		'required|string',
 			'status' =>				'in '.ZBX_SLA_STATUS_ENABLED,
+			'og_min_down_severity' =>	'in '.implode(',', range(0, 5)),
 			'excluded_downtimes' =>	'array'
 		];
 
@@ -94,7 +95,7 @@ class CControllerSlaCreate extends CControllerSlaCreateUpdate {
 			'excluded_downtimes' =>	[]
 		];
 
-		$fields = ['name', 'slo', 'period', 'timezone', 'description', 'excluded_downtimes'];
+		$fields = ['name', 'slo', 'period', 'timezone', 'description', 'og_min_down_severity', 'excluded_downtimes'];
 
 		$this->getInputs($sla, $fields);
 
diff --git a/ui/app/controllers/CControllerSlaEdit.php b/ui/app/controllers/CControllerSlaEdit.php
index 5b39ed5c049..5a4b1da28a0 100644
--- a/ui/app/controllers/CControllerSlaEdit.php
+++ b/ui/app/controllers/CControllerSlaEdit.php
@@ -55,7 +55,7 @@ class CControllerSlaEdit extends CController {
 
 		if ($this->hasInput('slaid')) {
 			$this->sla = API::Sla()->get([
-				'output' => ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description'],
+				'output' => ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description', 'og_min_down_severity'],
 				'selectServiceTags' => ['tag', 'operator', 'value'],
 				'selectSchedule' => ['period_from', 'period_to'],
 				'selectExcludedDowntimes' => ['name', 'period_from', 'period_to'],
@@ -112,6 +112,7 @@ class CControllerSlaEdit extends CController {
 					'service_tags' => $this->sla['service_tags'],
 					'description' => $this->sla['description'],
 					'status' => $this->sla['status'],
+					'og_min_down_severity' => $this->sla['og_min_down_severity'],
 					'excluded_downtimes' => $this->sla['excluded_downtimes']
 				]
 			];
@@ -132,6 +133,7 @@ class CControllerSlaEdit extends CController {
 					],
 					'description' => $defaults['description'],
 					'status' => ZBX_SLA_STATUS_ENABLED,
+					'og_min_down_severity' => $defaults['og_min_down_severity'],
 					'excluded_downtimes' => []
 				]
 			];
diff --git a/ui/app/controllers/CControllerSlaUpdate.php b/ui/app/controllers/CControllerSlaUpdate.php
index b1ec19b9698..def982c1537 100644
--- a/ui/app/controllers/CControllerSlaUpdate.php
+++ b/ui/app/controllers/CControllerSlaUpdate.php
@@ -39,6 +39,7 @@ class CControllerSlaUpdate extends CControllerSlaCreateUpdate {
 			'service_tags' =>		'required|array',
 			'description' =>		'required|string',
 			'status' =>				'in '.ZBX_SLA_STATUS_ENABLED,
+			'og_min_down_severity' =>	'in '.implode(',', range(0, 5)),
 			'excluded_downtimes' =>	'array'
 		];
 
@@ -105,7 +106,7 @@ class CControllerSlaUpdate extends CControllerSlaCreateUpdate {
 			'excluded_downtimes' =>	[]
 		];
 
-		$fields = ['slaid', 'name', 'slo', 'period', 'timezone', 'description', 'excluded_downtimes'];
+		$fields = ['slaid', 'name', 'slo', 'period', 'timezone', 'description', 'og_min_down_severity', 'excluded_downtimes'];
 
 		$this->getInputs($sla, $fields);
 
diff --git a/ui/app/views/sla.edit.php b/ui/app/views/sla.edit.php
index 524b7d52114..69fd98c7402 100644
--- a/ui/app/views/sla.edit.php
+++ b/ui/app/views/sla.edit.php
@@ -64,6 +64,18 @@ $sla_tab = (new CFormGrid())
 			' %'
 		])
 	])
+	->addItem([
+		new CLabel(_('Minimum severity for downtime'), 'og_min_down_severity'),
+		new CFormField(
+			(new CSelect('og_min_down_severity'))
+				->setId('og_min_down_severity')
+				->setValue((int) $data['form']['og_min_down_severity'])
+				->addOptions(array_map(
+					fn(int $s) => new CSelectOption($s, CSeverityHelper::getName($s)),
+					range(TRIGGER_SEVERITY_NOT_CLASSIFIED, TRIGGER_SEVERITY_DISASTER)
+				))
+		)
+	])
 	->addItem([
 		new CLabel(_('Reporting period')),
 		new CFormField(
diff --git a/ui/include/classes/api/services/CSla.php b/ui/include/classes/api/services/CSla.php
index b87e0892f61..0611adb0173 100644
--- a/ui/include/classes/api/services/CSla.php
+++ b/ui/include/classes/api/services/CSla.php
@@ -49,20 +49,20 @@ class CSla extends CApiService {
 				'operator' =>					['type' => API_INT32, 'in' => implode(',', [TAG_OPERATOR_LIKE, TAG_OPERATOR_EQUAL, TAG_OPERATOR_NOT_LIKE, TAG_OPERATOR_NOT_EQUAL, TAG_OPERATOR_EXISTS, TAG_OPERATOR_NOT_EXISTS])]
 			]],
 			'serviceids' =>					['type' => API_IDS, 'flags' => API_ALLOW_NULL | API_NORMALIZE, 'default' => null],
-			'filter' =>						['type' => API_FILTER, 'flags' => API_ALLOW_NULL, 'default' => null, 'fields' => ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status']],
+			'filter' =>						['type' => API_FILTER, 'flags' => API_ALLOW_NULL, 'default' => null, 'fields' => ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'og_min_down_severity']],
 			'search' =>						['type' => API_FILTER, 'flags' => API_ALLOW_NULL, 'default' => null, 'fields' => ['name', 'timezone', 'description']],
 			'searchByAny' =>				['type' => API_BOOLEAN, 'default' => false],
 			'startSearch' =>				['type' => API_FLAG, 'default' => false],
 			'excludeSearch' =>				['type' => API_FLAG, 'default' => false],
 			'searchWildcardsEnabled' =>		['type' => API_BOOLEAN, 'default' => false],
 			// output
-			'output' =>						['type' => API_OUTPUT, 'in' => implode(',', ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description']), 'default' => API_OUTPUT_EXTEND],
+			'output' =>						['type' => API_OUTPUT, 'in' => implode(',', ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description', 'og_min_down_severity']), 'default' => API_OUTPUT_EXTEND],
 			'countOutput' =>				['type' => API_FLAG, 'default' => false],
 			'selectServiceTags' =>			['type' => API_OUTPUT, 'flags' => API_ALLOW_NULL | API_ALLOW_COUNT, 'in' => implode(',', ['tag', 'operator', 'value']), 'default' => null],
 			'selectSchedule' =>				['type' => API_OUTPUT, 'flags' => API_ALLOW_NULL | API_ALLOW_COUNT, 'in' => implode(',', ['period_from', 'period_to']), 'default' => null],
 			'selectExcludedDowntimes' =>	['type' => API_OUTPUT, 'flags' => API_ALLOW_NULL | API_ALLOW_COUNT, 'in' => implode(',', ['name', 'period_from', 'period_to']), 'default' => null],
 			// sort and limit
-			'sortfield' =>					['type' => API_STRINGS_UTF8, 'flags' => API_NORMALIZE, 'in' => implode(',', ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description']), 'uniq' => true, 'default' => []],
+			'sortfield' =>					['type' => API_STRINGS_UTF8, 'flags' => API_NORMALIZE, 'in' => implode(',', ['slaid', 'name', 'period', 'slo', 'effective_date', 'timezone', 'status', 'description', 'og_min_down_severity']), 'uniq' => true, 'default' => []],
 			'sortorder' =>					['type' => API_SORTORDER, 'default' => []],
 			'limit' =>						['type' => API_INT32, 'flags' => API_ALLOW_NULL, 'in' => '1:'.ZBX_MAX_INT32, 'default' => null],
 			// flags
@@ -158,6 +158,7 @@ class CSla extends CApiService {
 			'timezone' =>			['type' => API_STRING_UTF8, 'flags' => API_REQUIRED, 'in' => implode(',', array_merge([ZBX_DEFAULT_TIMEZONE], array_keys(CTimezoneHelper::getList()))), 'length' => DB::getFieldLength('sla', 'timezone')],
 			'status' =>				['type' => API_INT32, 'in' => implode(',', [ZBX_SLA_STATUS_DISABLED, ZBX_SLA_STATUS_ENABLED])],
 			'description' =>		['type' => API_STRING_UTF8, 'length' => DB::getFieldLength('sla', 'description')],
+			'og_min_down_severity' =>	['type' => API_INT32, 'in' => implode(',', range(0, 5)), 'default' => DB::getDefault('sla', 'og_min_down_severity')],
 			'service_tags' =>		['type' => API_OBJECTS, 'flags' => API_REQUIRED | API_NOT_EMPTY, 'uniq' => [['tag', 'value']], 'fields' => [
 				'tag' =>				['type' => API_STRING_UTF8, 'flags' => API_REQUIRED | API_NOT_EMPTY, 'length' => DB::getFieldLength('sla_service_tag', 'tag')],
 				'operator' =>			['type' => API_INT32, 'in' => implode(',', [ZBX_SLA_SERVICE_TAG_OPERATOR_EQUAL, ZBX_SLA_SERVICE_TAG_OPERATOR_LIKE]), 'default' => DB::getDefault('sla_service_tag', 'operator')],
@@ -236,6 +237,7 @@ class CSla extends CApiService {
 			'timezone' =>			['type' => API_STRING_UTF8, 'in' => implode(',', array_merge([ZBX_DEFAULT_TIMEZONE], array_keys(CTimezoneHelper::getList()))), 'length' => DB::getFieldLength('sla', 'timezone')],
 			'status' =>				['type' => API_INT32, 'in' => implode(',', [ZBX_SLA_STATUS_DISABLED, ZBX_SLA_STATUS_ENABLED])],
 			'description' =>		['type' => API_STRING_UTF8, 'length' => DB::getFieldLength('sla', 'description')],
+			'og_min_down_severity' =>	['type' => API_INT32, 'in' => implode(',', range(0, 5))],
 			'service_tags' =>		['type' => API_OBJECTS, 'flags' => API_NOT_EMPTY, 'uniq' => [['tag', 'value']], 'fields' => [
 				'tag' =>				['type' => API_STRING_UTF8, 'flags' => API_REQUIRED | API_NOT_EMPTY, 'length' => DB::getFieldLength('sla_service_tag', 'tag')],
 				'operator' =>			['type' => API_INT32, 'in' => implode(',', [ZBX_SLA_SERVICE_TAG_OPERATOR_EQUAL, ZBX_SLA_SERVICE_TAG_OPERATOR_LIKE]), 'default' => DB::getDefault('sla_service_tag', 'operator')],
@@ -1058,7 +1060,7 @@ class CSla extends CApiService {
 		}
 
 		$db_sla = $this->get([
-			'output' => ['period', 'slo', 'timezone', 'effective_date'],
+			'output' => ['period', 'slo', 'timezone', 'effective_date', 'og_min_down_severity'],
 			'selectSchedule' => ['period_from', 'period_to'],
 			'selectExcludedDowntimes' => ['name', 'period_from', 'period_to'],
 			'slaids' => $options['slaid']
@@ -1324,7 +1326,9 @@ class CSla extends CApiService {
 							}
 						}
 
-						if ($prev_value == ZBX_SEVERITY_OK) {
+						// ZBX_SEVERITY_OK is -1; with default threshold 0, only OK counts as uptime
+						// (preserving original behavior). Higher thresholds treat lower severities as uptime.
+						if ($prev_value == ZBX_SEVERITY_OK || $prev_value < $db_sla['og_min_down_severity']) {
 							$cell['uptime'] += $uptime;
 						}
 						else {
diff --git a/ui/include/schema.inc.php b/ui/include/schema.inc.php
index a272bc1a430..dc7135668b7 100644
--- a/ui/include/schema.inc.php
+++ b/ui/include/schema.inc.php
@@ -8929,6 +8929,12 @@ return [
 				'type' => DB::FIELD_TYPE_TEXT,
 				'length' => 65535,
 				'default' => ''
+			],
+			'og_min_down_severity' => [
+				'null' => false,
+				'type' => DB::FIELD_TYPE_INT,
+				'length' => 10,
+				'default' => '0'
 			]
 		]
 	],