diff --git a/stable/prometheus-adapter/Chart.yaml b/stable/prometheus-adapter/Chart.yaml
index 4ad4013775..d7d22d5b6f 100644
--- a/stable/prometheus-adapter/Chart.yaml
+++ b/stable/prometheus-adapter/Chart.yaml
@@ -1,6 +1,6 @@
 name: prometheus-adapter
-version: v0.4.2
-appVersion: v0.4.1
+version: v0.5.0
+appVersion: v0.5.0
 description: A Helm chart for k8s prometheus adapter
 home: https://github.com/DirectXMan12/k8s-prometheus-adapter
 keywords:
diff --git a/stable/prometheus-adapter/README.md b/stable/prometheus-adapter/README.md
index 5650f26429..86fd4ce857 100644
--- a/stable/prometheus-adapter/README.md
+++ b/stable/prometheus-adapter/README.md
@@ -38,7 +38,7 @@ The following table lists the configurable parameters of the Prometheus Adapter
 | ------------------------------- | ------------------------------------------------------------------------------- | --------------------------------------------|
 | `affinity`                      | Node affinity                                                                   | `{}`                                        |
 | `image.repository`              | Image repository                                                                | `directxman12/k8s-prometheus-adapter-amd64` |
-| `image.tag`                     | Image tag                                                                       | `v0.4.1`                                    |
+| `image.tag`                     | Image tag                                                                       | `v0.5.0`                                    |
 | `image.pullPolicy`              | Image pull policy                                                               | `IfNotPresent`                              |
 | `image.pullSecrets`             | Image pull secrets                                                              | `{}`                                        |
 | `logLevel`                      | Log level                                                                       | `4`                                         |
@@ -50,7 +50,8 @@ The following table lists the configurable parameters of the Prometheus Adapter
 | `resources`                     | CPU/Memory resource requests/limits                                             | `{}`                                        |
 | `rules.default`                 | If `true`, enable a set of default rules in the configmap                       | `true`                                      |
 | `rules.custom`                  | A list of custom configmap rules                                                | `[]`                                        |
-| `rules.existing`                | The name of an existing configMap with rules. Overrides default and custom.     | ``                                          |
+| `rules.existing`                | The name of an existing configMap with rules. Overrides default, custom and external. | ``                                    |
+| `rules.external`                | A list of custom rules for external metrics API                                 | `[]`                                        |
 | `service.annotations`           | Annotations to add to the service                                               | `{}`                                        |
 | `service.port`                  | Service port to expose                                                          | `443`                                       |
 | `service.type`                  | Type of service to create                                                       | `ClusterIP`                                 |
diff --git a/stable/prometheus-adapter/templates/custom-metrics-configmap.yaml b/stable/prometheus-adapter/templates/custom-metrics-configmap.yaml
index e30aefd8f5..2d7f019f3d 100644
--- a/stable/prometheus-adapter/templates/custom-metrics-configmap.yaml
+++ b/stable/prometheus-adapter/templates/custom-metrics-configmap.yaml
@@ -82,4 +82,8 @@ data:
 {{- if .Values.rules.custom }}
 {{ toYaml .Values.rules.custom | indent 4 }}
 {{- end -}}
-{{- end -}}
\ No newline at end of file
+{{- if .Values.rules.external }}
+    externalRules:
+{{ toYaml .Values.rules.external | indent 4 }}
+{{- end -}}
+{{- end -}}
diff --git a/stable/prometheus-adapter/templates/external-metrics-apiservice.yaml b/stable/prometheus-adapter/templates/external-metrics-apiservice.yaml
new file mode 100644
index 0000000000..13de1c4bc6
--- /dev/null
+++ b/stable/prometheus-adapter/templates/external-metrics-apiservice.yaml
@@ -0,0 +1,21 @@
+apiVersion: apiregistration.k8s.io/v1beta1
+kind: APIService
+metadata:
+  labels:
+    app: {{ template "k8s-prometheus-adapter.name" . }}
+    chart: {{ template "k8s-prometheus-adapter.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+  name: v1beta1.external.metrics.k8s.io
+spec:
+  service:
+    name: {{ template "k8s-prometheus-adapter.fullname" . }}
+    namespace: {{ .Release.Namespace | quote }}
+  {{ if .Values.tls.enable -}}
+  caBundle: {{ b64enc .Values.tls.ca }}
+  {{- end }}
+  group: external.metrics.k8s.io
+  version: v1beta1
+  insecureSkipTLSVerify: {{ if .Values.tls.enable }}false{{ else }}true{{ end }}
+  groupPriorityMinimum: 100
+  versionPriority: 100
diff --git a/stable/prometheus-adapter/templates/external-metrics-cluster-role.yaml b/stable/prometheus-adapter/templates/external-metrics-cluster-role.yaml
new file mode 100644
index 0000000000..daa1d03a05
--- /dev/null
+++ b/stable/prometheus-adapter/templates/external-metrics-cluster-role.yaml
@@ -0,0 +1,20 @@
+{{- if .Values.rbac.create -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  labels:
+    app: {{ template "k8s-prometheus-adapter.name" . }}
+    chart: {{ template "k8s-prometheus-adapter.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+  name: {{ template "k8s-prometheus-adapter.name" . }}-external-metrics
+rules:
+- apiGroups:
+  - "external.metrics.k8s.io"
+  resources:
+  - "*"
+  verbs:
+  - list
+  - get
+  - watch
+{{- end -}}
diff --git a/stable/prometheus-adapter/templates/hpa-external-metrics-cluster-role-binding.yaml b/stable/prometheus-adapter/templates/hpa-external-metrics-cluster-role-binding.yaml
new file mode 100644
index 0000000000..f1d54f8b84
--- /dev/null
+++ b/stable/prometheus-adapter/templates/hpa-external-metrics-cluster-role-binding.yaml
@@ -0,0 +1,20 @@
+
+{{- if .Values.rbac.create -}}
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  labels:
+    app: {{ template "k8s-prometheus-adapter.name" . }}
+    chart: {{ template "k8s-prometheus-adapter.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+  name: {{ template "k8s-prometheus-adapter.name" . }}-hpa-controller-external-metrics
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: {{ template "k8s-prometheus-adapter.name" . }}-external-metrics
+subjects:
+- kind: ServiceAccount
+  name: horizontal-pod-autoscaler
+  namespace: kube-system
+{{- end -}}
diff --git a/stable/prometheus-adapter/values.yaml b/stable/prometheus-adapter/values.yaml
index 070bc462d2..28fc9f1469 100644
--- a/stable/prometheus-adapter/values.yaml
+++ b/stable/prometheus-adapter/values.yaml
@@ -3,7 +3,7 @@ affinity: {}
 
 image:
   repository: directxman12/k8s-prometheus-adapter-amd64
-  tag: v0.4.1
+  tag: v0.5.0
   pullPolicy: IfNotPresent
 
 logLevel: 4
@@ -49,8 +49,16 @@ rules:
 #     as: "my_custom_metric"
 #   metricsQuery: sum(<<.Series>>{<<.LabelMatchers>>}) by (<<.GroupBy>>)
   # Mounts a configMap with pre-generated rules for use. Overrides the
-  # default and custom entries
+  # default, custom and external entries
   existing:
+  external: []
+# - seriesQuery: '{__name__=~"^some_metric_count$"}'
+#   resources:
+#     template: <<.Resource>>
+#   name:
+#     matches: ""
+#     as: "my_custom_metric"
+#   metricsQuery: sum(<<.Series>>{<<.LabelMatchers>>}) by (<<.GroupBy>>)
 
 service:
   annotations: {}