This is the standard code to register (create) a custom post type. For more detailed information on these and other options check out the WordPress Codex page.

function register_post_types() {
    $labels = array( 
        'name' => _x( 'Practitioners', 'themeblvd' ),
        'singular_name' => _x( 'Practitioner', 'themeblvd' ),
        'add_new' => _x( 'Add New', 'themeblvd' ),
        'add_new_item' => _x( 'Add New Practitioner', 'themeblvd' ),
        'edit_item' => _x( 'Edit Practitioner', 'themeblvd' ),
        'new_item' => _x( 'New Practitioner', 'themeblvd' ),
        'view_item' => _x( 'View Practitioner', 'themeblvd' ),
        'search_items' => _x( 'Search Practitioners', 'themeblvd' ),
        'not_found' => _x( 'No practitioners found', 'themeblvd' ),
        'not_found_in_trash' => _x( 'No practitioners found in Trash', 'themeblvd' ),
        'parent_item_colon' => _x( 'Parent Practitioner:', 'themeblvd' ),
        'menu_name' => _x( 'Practitioners', 'themeblvd' ),
    );
    $args = array( 
        'labels' => $labels,
        'hierarchical' => false,
        'supports' => array( 'title', 'editor', 'custom-fields', 'thumbnail' ),
        'public' => true,
        'show_ui' => true,
        'show_in_menu' => true,
        'show_in_nav_menus' => true,
        'publicly_queryable' => true,
        'exclude_from_search' => false,
        'has_archive' => true,
        'query_var' => true,
        'can_export' => true,
        'rewrite' => array( 'slug' => 'practitioners'),
        'capability_type' => 'post'
    );
    register_post_type( 'practitioner', $args );
}
function register_custom_taxonomies() {
     $labels = array( 
        'name' => _x( 'State Name', 'themeblvd' ),
        'singular_name' => _x( 'State', 'themeblvd' ),
        'search_items' => _x( 'Search States', 'themeblvd' ),
        'popular_items' => _x( 'Popular States', 'themeblvd' ),
        'all_items' => _x( 'All States', 'themeblvd' ),
        'parent_item' => _x( 'Parent State', 'themeblvd' ),
        'parent_item_colon' => _x( 'Parent State:', 'themeblvd' ),
        'edit_item' => _x( 'Edit State', 'themeblvd' ),
        'update_item' => _x( 'Update State', 'themeblvd' ),
        'add_new_item' => _x( 'Add New State', 'themeblvd' ),
        'new_item_name' => _x( 'New State', 'themeblvd' ),
        'add_or_remove_items' => _x( 'Add or remove States', 'themeblvd' ),
        'choose_from_most_used' => _x( 'Choose from most used States', 'themeblvd' ),
        'menu_name' => _x( 'States', 'themeblvd' ),
    );
    $args = array( 
        'labels' => $labels,
        'public' => true,
        'show_in_nav_menus' => true,
        'show_ui' => true,
        'show_tagcloud' => true,
        'hierarchical' => true,
        'rewrite' => array( 'slug' => 'states'),
        'query_var' => 'state'
    );
    register_taxonomy( 'state', array('practitioner'), $args );
     $labels = array( 
        'name' => _x( 'Certification Name', 'themeblvd' ),
        'singular_name' => _x( 'Certification', 'themeblvd' ),
        'search_items' => _x( 'Search Certifications', 'themeblvd' ),
        'popular_items' => _x( 'Popular Certifications', 'themeblvd' ),
        'all_items' => _x( 'All Certifications', 'themeblvd' ),
        'parent_item' => _x( 'Parent Certification', 'themeblvd' ),
        'parent_item_colon' => _x( 'Parent Certification:', 'themeblvd' ),
        'edit_item' => _x( 'Edit Certification', 'themeblvd' ),
        'update_item' => _x( 'Update Certification', 'themeblvd' ),
        'add_new_item' => _x( 'Add New Certification', 'themeblvd' ),
        'new_item_name' => _x( 'New Certification', 'themeblvd' ),
        'add_or_remove_items' => _x( 'Add or remove Certifications', 'themeblvd' ),
        'choose_from_most_used' => _x( 'Choose from most used Certifications', 'themeblvd' ),
        'menu_name' => _x( 'Certifications', 'themeblvd' ),
    );
    $args = array( 
        'labels' => $labels,
        'public' => true,
        'show_in_nav_menus' => true,
        'show_ui' => true,
        'show_tagcloud' => true,
        'hierarchical' => true,
        'rewrite' => array( 'slug' => 'certifications'),
        'query_var' => 'certification'
    );
    register_taxonomy( 'certification', array('practitioner'), $args );
}
function my_cpt_init() {
    register_post_types();
	register_custom_taxonomies();
}
add_action( 'init', 'my_cpt_init' );
function my_rewrite_flush() {
    flush_rewrite_rules();
}
add_action( 'after_switch_theme', 'my_rewrite_flush' );

Notice “hierarchical” is set to true. This will cause the taxonomy to behave like a category. False or omitted causes the taxonomy to behave like a tag.