From Defense Industry Daily:

LPD-17 San Antonio class amphibious assault support vessels are just entering service with the US Navy, and 11 ships of this class are eventually slated to replace up to 41 previous ships. Much like their smaller predecessors, their mission is to embark, transport, land, and support elements of a US Marine Corps Landing Force. The difference is found in these ships’ size, their cost, and the capabilities and technologies used to perform those missions. Among other additions, this new ship is designed to operate the Marines’ new MV-22 Osprey tilt-rotor aircraft, alongside the standard well decks for hovercraft and amphibious armored personnel carriers.