Drupal Commerce: Get selected payment method programmatically
I don't think there's anything built in, but you can use an EntityFieldQuery to grab the transaction(s) related to the order, and from there the payment type(s) used:

$query = new \EntityFieldQuery();
$query-&gt;entityCondition('entity_type', 'commerce_payment_transaction')
  -&gt;propertyCondition('order_id', $order-&gt;order_id);

$results = $query-&gt;execute();
if (!empty($results['commerce_payment_transaction'])) {
  $transactions = entity_load('commerce_payment_transaction', array_keys($results['commerce_payment_transaction']));
  foreach ($transactions as $transaction) {
    $payment_method = $transaction-&gt;payment_method;
  }
}