Yes, virtually all large cruise ships in 2026 are required to have at least one licensed physician and several nurses onboard. Under the latest Cruise Lines International Association (CLIA) standards, medical facilities must be capable of providing emergency care, including stabilizing patients for medical evacuation. New regulations for 2026 even require many ships to have doctors trained in Point of Care Ultrasound (PoCUS) to better diagnose issues like DVT or internal trauma while at sea. While these infirmaries are highly advanced—often equipped with X-ray machines, labs, and ventilators—they are not full-service hospitals. Their primary role is to treat minor ailments and manage life-threatening emergencies until the patient can be transferred to a land-based facility. Note that on very small "expedition" vessels with fewer than 100 passengers, a doctor may not be legally mandated, though one is still usually present.