How Much Is a Flight to Mexico? Round-Trip Fares to Nine Mexican Cities, Embedded Government Charges and US–Mexico Nonstop Air Traffic from Fare-Search Data, Tax Law and BTS T-100 Segment Data, 1990–2026

Air travel between the United States and Mexico is one of the largest international markets served from US airports, yet fares and the charges inside them are rarely documented together with traffic. We combine a snapshot of published round-trip fare statistics for nine Mexican cities (27 September 2026), the US and Mexican laws and tariffs that set per-passenger taxes and fees, and the US Bureau of Transportation Statistics T-100 International Segment data for 1990–2025. Twelve-month average round trips from all US airports ranged from USD 413 to Monterrey to USD 672 to Veracruz, with Cancun at USD 514; the gap between a city's cheapest and priciest monthly median reached USD 281, more than the USD 259 spread across cities, and December was the priciest month for seven of nine cities. For a foreign visitor on a nonstop round trip, government charges came to USD 194.28 via Cancun and USD 212.30 via Mexico City, 37.8% and 42.9% of the average fares; the US share was USD 75.13 and Mexico's two federal fees USD 70.43. Nonstop flights carried a record 40,527,947 passengers in 2025, 31.4% above 2019 and 4.20 times 1990, but only 0.6% above 2024. Since 1990 the gain came mainly from fuller aircraft: seats filled rose from 59.8% to 79.2% while seats per flight moved from 158 to 164. Cancun handled 28.5% of passengers and Los Angeles–Guadalajara was the busiest route. All inputs are public.