Index: wp-admin/css/common.css
===================================================================
--- wp-admin/css/common.css	(revision 33877)
+++ wp-admin/css/common.css	(working copy)
@@ -1524,10 +1524,11 @@
 	background-position: bottom left;
 }
 
-#screen-options-wrap h5,
+#screen-options-wrap legend,
 #contextual-help-wrap h5 {
 	margin: 8px 0;
 	font-size: 13px;
+	font-weight: 600;
 }
 
 .metabox-prefs label {
Index: wp-admin/includes/screen.php
===================================================================
--- wp-admin/includes/screen.php	(revision 33877)
+++ wp-admin/includes/screen.php	(working copy)
@@ -1088,7 +1088,8 @@
 		<div id="screen-options-wrap" class="hidden" tabindex="-1" aria-label="<?php esc_attr_e('Screen Options Tab'); ?>">
 		<form id="adv-settings" method="post">
 		<?php if ( isset( $wp_meta_boxes[ $this->id ] ) || $this->get_option( 'per_page' ) || ( $columns && empty( $columns['_title'] ) ) ) : ?>
-			<h5><?php _e( 'Show on screen' ); ?></h5>
+			<fieldset>
+				<legend><?php _e( 'Show on screen' ); ?></legend>
 		<?php
 		endif;
 
@@ -1114,9 +1115,11 @@
 				<br class="clear" />
 			</div>
 			<?php endif;
+						
 			if ( $columns ) :
 				if ( ! empty( $columns['_title'] ) ) : ?>
-			<h5><?php echo $columns['_title']; ?></h5>
+			<fieldset>
+				<legend><?php echo $columns['_title']; ?></legend>
 			<?php endif; ?>
 			<div class="metabox-prefs">
 				<?php
@@ -1139,8 +1142,13 @@
 				?>
 				<br class="clear" />
 			</div>
+			<?php if ( ! empty( $columns['_title'] ) ) : ?>
+			</fieldset>
+			<?php endif; ?>			
 		<?php endif;
-
+		if ( isset( $wp_meta_boxes[ $this->id ] ) || $this->get_option( 'per_page' ) || ( $columns && empty( $columns['_title'] ) ) ) : ?>
+			</fieldset>
+		<?php endif;
 		$this->render_screen_layout();
 		$this->render_per_page_options();
 		echo $this->_screen_settings;
@@ -1165,19 +1173,21 @@
 		$num = $this->get_option( 'layout_columns', 'max' );
 
 		?>
-		<h5 class="screen-layout"><?php _e('Screen Layout'); ?></h5>
-		<div class='columns-prefs'><?php
-			_e('Number of Columns:');
-			for ( $i = 1; $i <= $num; ++$i ):
-				?>
-				<label class="columns-prefs-<?php echo $i; ?>">
-					<input type='radio' name='screen_columns' value='<?php echo esc_attr( $i ); ?>'
-						<?php checked( $screen_layout_columns, $i ); ?> />
-					<?php echo esc_html( $i ); ?>
-				</label>
-				<?php
-			endfor; ?>
+		<fieldset>
+		<legend class="screen-layout"><?php _e('Screen Layout'); ?></legend>
+		<div class='columns-prefs'>
+			<span id='number-of-columns'><?php _e('Number of Columns:'); ?></span><?php
+				for ( $i = 1; $i <= $num; ++$i ):
+					?>
+					<label class="columns-prefs-<?php echo $i; ?>">
+						<input type='radio' name='screen_columns' aria-describedby='number-of-columns' value='<?php echo esc_attr( $i ); ?>'
+							<?php checked( $screen_layout_columns, $i ); ?> />
+						<?php echo esc_html( $i ); ?>
+					</label>
+					<?php
+				endfor; ?>
 		</div>
+		</fieldset>
 		<?php
 	}