diff --git a/client/mdm/canonical_loaders.go b/client/mdm/canonical_loaders.go
index cb9af9ccb..29288b511 100644
--- a/client/mdm/canonical_loaders.go
+++ b/client/mdm/canonical_loaders.go
@@ -22,6 +22,7 @@ var allKeys = []string{
 	KeyDisableMetricsCollection,
 	KeyAllowServerSSH,
 	KeyDisableAutoConnect,
+	KeyDisableAutostart,
 	KeyPreSharedKey,
 	KeyRosenpassEnabled,
 	KeyRosenpassPermissive,
diff --git a/client/mdm/policy.go b/client/mdm/policy.go
index b76c70a75..1feff28f8 100644
--- a/client/mdm/policy.go
+++ b/client/mdm/policy.go
@@ -20,10 +20,10 @@ import (
 // names (lowerCamelCase) so the daemon can map a Policy key directly to a
 // configuration field.
 const (
-	KeyManagementURL            = "managementURL"
-	KeyDisableUpdateSettings    = "disableUpdateSettings"
-	KeyDisableProfiles          = "disableProfiles"
-	KeyDisableNetworks          = "disableNetworks"
+	KeyManagementURL         = "managementURL"
+	KeyDisableUpdateSettings = "disableUpdateSettings"
+	KeyDisableProfiles       = "disableProfiles"
+	KeyDisableNetworks       = "disableNetworks"
 	// KeyDisableAdvancedView gates the advanced-view section in the
 	// upcoming UI revision. UI-only: NOT stored on Config, not
 	// applied by applyMDMPolicy, not rejectable via SetConfig. The
@@ -37,10 +37,16 @@ const (
 	KeyDisableMetricsCollection = "disableMetricsCollection"
 	KeyAllowServerSSH           = "allowServerSSH"
 	KeyDisableAutoConnect       = "disableAutoConnect"
-	KeyPreSharedKey             = "preSharedKey"
-	KeyRosenpassEnabled         = "rosenpassEnabled"
-	KeyRosenpassPermissive      = "rosenpassPermissive"
-	KeyWireguardPort            = "wireguardPort"
+	// KeyDisableAutostart suppresses the GUI's fresh-install
+	// launch-on-login default and marks the Settings toggle as
+	// MDM-managed. UI-only: NOT stored on Config and not applied by
+	// applyMDMPolicy; the GUI reads it directly and it appears in
+	// GetConfigResponse.mDMManagedFields when set.
+	KeyDisableAutostart    = "disableAutostart"
+	KeyPreSharedKey        = "preSharedKey"
+	KeyRosenpassEnabled    = "rosenpassEnabled"
+	KeyRosenpassPermissive = "rosenpassPermissive"
+	KeyWireguardPort       = "wireguardPort"
 
 	// Split tunnel is modeled as a single conceptual policy with two
 	// registry/plist values. KeySplitTunnelMode is the discriminator
diff --git a/client/ui/preferences/store.go b/client/ui/preferences/store.go
index afc854185..2f81d7225 100644
--- a/client/ui/preferences/store.go
+++ b/client/ui/preferences/store.go
@@ -54,6 +54,10 @@ type UIPreferences struct {
 	Language            i18n.LanguageCode `json:"language"`
 	ViewMode            ViewMode          `json:"viewMode"`
 	OnboardingCompleted bool              `json:"onboardingCompleted"`
+	// AutostartInitialized records that the one-time autostart default
+	// decision has run for this OS user. It only ever transitions to true
+	// and is never reset, so the default-on flow runs at most once, ever.
+	AutostartInitialized bool `json:"autostartInitialized"`
 }
 
 // LanguageValidator rejects SetLanguage inputs with no shipped bundle.
@@ -157,6 +161,27 @@ func (s *Store) SetOnboardingCompleted(done bool) error {
 	return nil
 }
 
+// SetAutostartInitialized persists the one-time autostart decision marker.
+// No-op if unchanged.
+func (s *Store) SetAutostartInitialized(done bool) error {
+	s.mu.Lock()
+	if s.current.AutostartInitialized == done {
+		s.mu.Unlock()
+		return nil
+	}
+	next := s.current
+	next.AutostartInitialized = done
+	if err := s.persistLocked(next); err != nil {
+		s.mu.Unlock()
+		return fmt.Errorf("persist preferences: %w", err)
+	}
+	s.current = next
+	s.mu.Unlock()
+
+	s.broadcast(next)
+	return nil
+}
+
 // SetLanguage validates, persists, and broadcasts. No-op if unchanged.
 func (s *Store) SetLanguage(lang i18n.LanguageCode) error {
 	if lang == "" {
diff --git a/client/ui/preferences/store_test.go b/client/ui/preferences/store_test.go
index 0d1cc7b54..71c52038f 100644
--- a/client/ui/preferences/store_test.go
+++ b/client/ui/preferences/store_test.go
@@ -215,6 +215,29 @@ func TestStore_FileShapeIsJSON(t *testing.T) {
 	assert.Equal(t, i18n.LanguageCode("hu"), parsed.Language)
 }
 
+func TestStore_SetAutostartInitializedPersistsAcrossReload(t *testing.T) {
+	withTempConfigDir(t)
+	emitter := &recordingEmitter{}
+	s, err := NewStore(nil, emitter)
+	require.NoError(t, err)
+
+	assert.False(t, s.Get().AutostartInitialized, "marker must default to false when no file is on disk")
+
+	require.NoError(t, s.SetAutostartInitialized(true))
+	assert.True(t, s.Get().AutostartInitialized, "Get should reflect the persisted marker")
+	require.Len(t, emitter.calledWith(EventPreferencesChanged), 1, "first marker write should broadcast")
+
+	// Re-setting the same value must be a no-op: no disk write, no broadcast.
+	require.NoError(t, s.SetAutostartInitialized(true))
+	assert.Len(t, emitter.calledWith(EventPreferencesChanged), 1, "idempotent marker write should not broadcast again")
+
+	// A fresh Store (new GUI launch) must see the marker so the autostart
+	// default decision never runs twice.
+	reloaded, err := NewStore(nil, nil)
+	require.NoError(t, err)
+	assert.True(t, reloaded.Get().AutostartInitialized, "marker must survive a reload from disk")
+}
+
 func TestStore_ErrUnsupportedSentinel(t *testing.T) {
 	// Verifies callers can match on the sentinel error rather than parsing
 	// strings — protects against accidental %v -> %w changes that would
diff --git a/client/ui/services/settings.go b/client/ui/services/settings.go
index 1c16795ae..3b6f6f81b 100644
--- a/client/ui/services/settings.go
+++ b/client/ui/services/settings.go
@@ -20,11 +20,12 @@ type MDMFields struct {
 	DisableServerRoutes      bool   `json:"disableServerRoutes"`
 	AllowServerSSH           *bool  `json:"allowServerSSH"`
 	DisableAutoConnect       bool   `json:"disableAutoConnect"`
+	DisableAutostart         bool   `json:"disableAutostart"`
 	BlockInbound             bool   `json:"blockInbound"`
 	DisableMetricsCollection bool   `json:"disableMetricsCollection"`
 	SplitTunnelMode          bool   `json:"splitTunnelMode"`
 	SplitTunnelApps          bool   `json:"splitTunnelApps"`
-	DisableAdvancedView bool `json:"disableAdvancedView"`
+	DisableAdvancedView      bool   `json:"disableAdvancedView"`
 }
 
 type Features struct {