diff --git a/pkg/services/ngalert/api/tooling/definitions/alertmanager.go b/pkg/services/ngalert/api/tooling/definitions/alertmanager.go
index 25dce197f52..b701f74a3bb 100644
--- a/pkg/services/ngalert/api/tooling/definitions/alertmanager.go
+++ b/pkg/services/ngalert/api/tooling/definitions/alertmanager.go
@@ -746,6 +746,9 @@ func (c *Config) UnmarshalJSON(b []byte) error {
 	if len(c.Route.Match) > 0 || len(c.Route.MatchRE) > 0 {
 		return fmt.Errorf("root route must not have any matchers")
 	}
+	if len(c.Route.MuteTimeIntervals) > 0 {
+		return fmt.Errorf("root route must not have any mute time intervals")
+	}
 
 	for _, r := range c.InhibitRules {
 		if err := r.UnmarshalYAML(noopUnmarshal); err != nil {
@@ -753,6 +756,33 @@ func (c *Config) UnmarshalJSON(b []byte) error {
 		}
 	}
 
+	tiNames := make(map[string]struct{})
+	for _, mt := range c.MuteTimeIntervals {
+		if mt.Name == "" {
+			return fmt.Errorf("missing name in mute time interval")
+		}
+		if _, ok := tiNames[mt.Name]; ok {
+			return fmt.Errorf("mute time interval %q is not unique", mt.Name)
+		}
+		tiNames[mt.Name] = struct{}{}
+	}
+	return checkTimeInterval(c.Route, tiNames)
+}
+
+func checkTimeInterval(r *Route, timeIntervals map[string]struct{}) error {
+	for _, sr := range r.Routes {
+		if err := checkTimeInterval(sr, timeIntervals); err != nil {
+			return err
+		}
+	}
+	if len(r.MuteTimeIntervals) == 0 {
+		return nil
+	}
+	for _, mt := range r.MuteTimeIntervals {
+		if _, ok := timeIntervals[mt]; !ok {
+			return fmt.Errorf("undefined time interval %q used in route", mt)
+		}
+	}
 	return nil
 }
 
diff --git a/pkg/services/ngalert/api/tooling/definitions/alertmanager_test.go b/pkg/services/ngalert/api/tooling/definitions/alertmanager_test.go
index d6be3625476..a5c88d01621 100644
--- a/pkg/services/ngalert/api/tooling/definitions/alertmanager_test.go
+++ b/pkg/services/ngalert/api/tooling/definitions/alertmanager_test.go
@@ -2,6 +2,7 @@ package definitions
 
 import (
 	"encoding/json"
+	"errors"
 	"io/ioutil"
 	"strings"
 	"testing"
@@ -405,6 +406,283 @@ email_configs:
 	}
 }
 
+func Test_ConfigUnmashaling(t *testing.T) {
+	for _, tc := range []struct {
+		desc, input string
+		err         error
+	}{
+		{
+			desc: "empty mute time name should error",
+			err:  errors.New("missing name in mute time interval"),
+			input: `
+				{
+				  "route": {
+					"receiver": "grafana-default-email"
+				  },
+				  "mute_time_intervals": [
+					{
+					  "name": "",
+					  "time_intervals": [
+						{
+						  "times": [
+							{
+							  "start_time": "00:00",
+							  "end_time": "12:00"
+							}
+						  ]
+						}
+					  ]
+					}
+				  ],
+				  "templates": null,
+				  "receivers": [
+					{
+					  "name": "grafana-default-email",
+					  "grafana_managed_receiver_configs": [
+						{
+						  "uid": "uxwfZvtnz",
+						  "name": "email receiver",
+						  "type": "email",
+						  "disableResolveMessage": false,
+						  "settings": {
+							"addresses": "<example@email.com>"
+						  },
+						  "secureFields": {}
+						}
+					  ]
+					}
+				  ]
+				}
+			`,
+		},
+		{
+			desc: "not unique mute time names should error",
+			err:  errors.New("mute time interval \"test1\" is not unique"),
+			input: `
+				{
+				  "route": {
+					"receiver": "grafana-default-email"
+				  },
+				  "mute_time_intervals": [
+					{
+					  "name": "test1",
+					  "time_intervals": [
+						{
+						  "times": [
+							{
+							  "start_time": "00:00",
+							  "end_time": "12:00"
+							}
+						  ]
+						}
+					  ]
+					},
+					{
+						"name": "test1",
+						"time_intervals": [
+						  {
+							"times": [
+							  {
+								"start_time": "00:00",
+								"end_time": "12:00"
+							  }
+							]
+						  }
+						]
+					  }
+				  ],
+				  "templates": null,
+				  "receivers": [
+					{
+					  "name": "grafana-default-email",
+					  "grafana_managed_receiver_configs": [
+						{
+						  "uid": "uxwfZvtnz",
+						  "name": "email receiver",
+						  "type": "email",
+						  "disableResolveMessage": false,
+						  "settings": {
+							"addresses": "<example@email.com>"
+						  },
+						  "secureFields": {}
+						}
+					  ]
+					}
+				  ]
+				}
+			`,
+		},
+		{
+			desc: "mute time intervals on root route should error",
+			err:  errors.New("root route must not have any mute time intervals"),
+			input: `
+				{
+				  "route": {
+					"receiver": "grafana-default-email",
+					"mute_time_intervals": ["test1"]
+				  },
+				  "mute_time_intervals": [
+					{
+					  "name": "test1",
+					  "time_intervals": [
+						{
+						  "times": [
+							{
+							  "start_time": "00:00",
+							  "end_time": "12:00"
+							}
+						  ]
+						}
+					  ]
+					}
+				  ],
+				  "templates": null,
+				  "receivers": [
+					{
+					  "name": "grafana-default-email",
+					  "grafana_managed_receiver_configs": [
+						{
+						  "uid": "uxwfZvtnz",
+						  "name": "email receiver",
+						  "type": "email",
+						  "disableResolveMessage": false,
+						  "settings": {
+							"addresses": "<example@email.com>"
+						  },
+						  "secureFields": {}
+						}
+					  ]
+					}
+				  ]
+				}
+			`,
+		},
+		{
+			desc: "undefined mute time names in routes should error",
+			err:  errors.New("undefined time interval \"test2\" used in route"),
+			input: `
+				{
+				  "route": {
+					"receiver": "grafana-default-email",
+					"routes": [
+						{
+						  "receiver": "grafana-default-email",
+						  "object_matchers": [
+							[
+							  "a",
+							  "=",
+							  "b"
+							]
+						  ],
+						  "mute_time_intervals": [
+							"test2"
+						  ]
+						}
+					  ]
+				  },
+				  "mute_time_intervals": [
+					{
+					  "name": "test1",
+					  "time_intervals": [
+						{
+						  "times": [
+							{
+							  "start_time": "00:00",
+							  "end_time": "12:00"
+							}
+						  ]
+						}
+					  ]
+					}
+				  ],
+				  "templates": null,
+				  "receivers": [
+					{
+					  "name": "grafana-default-email",
+					  "grafana_managed_receiver_configs": [
+						{
+						  "uid": "uxwfZvtnz",
+						  "name": "email receiver",
+						  "type": "email",
+						  "disableResolveMessage": false,
+						  "settings": {
+							"addresses": "<example@email.com>"
+						  },
+						  "secureFields": {}
+						}
+					  ]
+					}
+				  ]
+				}
+			`,
+		},
+		{
+			desc: "valid config should not error",
+			input: `
+				{
+				  "route": {
+					"receiver": "grafana-default-email",
+					"routes": [
+						{
+						  "receiver": "grafana-default-email",
+						  "object_matchers": [
+							[
+							  "a",
+							  "=",
+							  "b"
+							]
+						  ],
+						  "mute_time_intervals": [
+							"test1"
+						  ]
+						}
+					  ]
+				  },
+				  "mute_time_intervals": [
+					{
+					  "name": "test1",
+					  "time_intervals": [
+						{
+						  "times": [
+							{
+							  "start_time": "00:00",
+							  "end_time": "12:00"
+							}
+						  ]
+						}
+					  ]
+					}
+				  ],
+				  "templates": null,
+				  "receivers": [
+					{
+					  "name": "grafana-default-email",
+					  "grafana_managed_receiver_configs": [
+						{
+						  "uid": "uxwfZvtnz",
+						  "name": "email receiver",
+						  "type": "email",
+						  "disableResolveMessage": false,
+						  "settings": {
+							"addresses": "<example@email.com>"
+						  },
+						  "secureFields": {}
+						}
+					  ]
+					}
+				  ]
+				}
+			`,
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+			var out Config
+			err := json.Unmarshal([]byte(tc.input), &out)
+			require.Equal(t, tc.err, err)
+		})
+	}
+}
+
 func Test_GettableUserConfigUnmarshaling(t *testing.T) {
 	for _, tc := range []struct {
 		desc, input string