if (data.contractType == "КПП") {
$("#maxPaymentTermDiv").show();
} else {
$("#maxPaymentTermDiv").hide();
}
<div class="col-sm-4" id="maxPaymentTermDiv">
<label for="maxPaymentTerm">Максимальный срок выплаты</label>
<input
type="text"
class="form-control"
id="maxPaymentTerm"
/>
</div>