Give members of specific level IDs Free Shipping in your WooCommerce store.

my_pmprowc_free_shipping.php

/*
 * Give members of level 1 or 2 Free Shipping when free shipping is available (must set free shipping as an option in store settings).
 * Change $pmprowc_free_shipping_levels = array(1,2); to include level IDs that receive free shipping
*/
function my_pmprowc_free_shipping( $rates, $package ) {
	$pmprowc_free_shipping_levels = array( '1', '2' );

	$free_shipping_key = "";
	foreach( $rates as $key => $val ){
		if( strpos( $key, 'free_shipping' ) !== false ){
			$free_shipping_key = $key;
		}
	}

	if(function_exists('pmpro_hasMembershipLevel') && isset( $rates[$free_shipping_key] ) && pmpro_hasMembershipLevel($pmprowc_free_shipping_levels) )
	{
		// Get Free Shipping array into a new array
		$freeshipping = array();
		$freeshipping = $rates[$free_shipping_key];
 
		// Empty the $available_methods array
		unset( $rates );
 
		// Add Free Shipping back into $avaialble_methods
		$rates = array();
		$rates[] = $freeshipping;
	}
	else
	{
		// remove free shipping option
		unset( $rates[$free_shipping_key] );
	}
	
	return $rates;
}
add_filter( 'woocommerce_package_rates', 'my_pmprowc_free_shipping' , 10, 2 );

This recipe is included in the blog post on " Give Members “Free Shipping” at Shop Checkout using Jigoshop or WooCommerce" at Paid Memberships Pro here: https://www.paidmembershipspro.com/give-members-free-shipping-at-shop-checkout/