Frontier Airlines is plotting a big network shake-up that's set to take effect right before the peak 2025 summer travel season gets into full swing. The Denver-based ultra-low-cost carrier will add more than a dozen new routes in May at airports across the country — including a new route to the northwest tip of Puerto Rico.

Frontier will begin flying three new daily routes between Washington Dulles (IAD) and Dallas-Fort Worth (DFW), Miami and San Juan, Puerto Rico (SJU). Travelers heading from SJU can also enjoy thrice weekly flights to IAD.