Raw

<input id="maskedtextbox" />
<script>
$("#maskedtextbox").kendoMaskedTextBox({
    mask: "(000)-000",
    value: "(123)-456"
});

var maskedtextbox = $("#maskedtextbox").data("kendoMaskedTextBox");

var raw = maskedtextbox.raw(); //the result value will be "123456"

/* The result can be observed in the DevTools(F12) console of the browser. */
console.log(raw);
</script>