you need to add ng-model and ng-change event like below.

and in your controller you can defined function as following. $scope.showSelected= function(){ console.log($scope.selectedVal); }

you need to add ng-model and ng-change event like below.

<md-radio-group ng-model="selectedVal" ng-change="showSelected()">

and in your controller you can defined function as following. $scope.showSelected= function(){ console.log($scope.selectedVal); }