Major carriers operating routes between Newark Liberty International Airport (EWR) and Las Américas International Airport (SDQ) in December include United, JetBlue, American, and low-cost options like Spirit (service varies seasonally). United often offers nonstop service from EWR with full‑service perks (checked bag allowances on many fares and loyalty benefits), JetBlue provides extra legroom and free Wi‑Fi on many flights but may operate from nearby JFK as well, American offers competitive one‑stop options via hubs like Charlotte, and Spirit sells lower base fares with fees for carry-on and checked bags. When comparing airlines in December, factor in total trip cost (base fare plus baggage and seat fees), schedule convenience, and loyalty benefits — for holiday travel, paying slightly more for a convenient nonstop and generous baggage allowance can be worth avoiding delays and extra fees.