United Flight UA2021 Deals & Information (2025/2026)

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United Flight 2021 Route Deals From $99

The cheapest prices found with in the last 7 days for return flights were $198 and $99 for one-way flights to Luis Munoz Marin Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Mon, Oct 6 - Wed, Oct 22
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$198 Roundtrip, found 2 days ago
$198
Roundtrip
found 2 days ago
Select United flight, departing Mon, Oct 6 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Wed, Oct 22, priced at $198 found 2 days ago
Sun, Nov 9 - Thu, Nov 13
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$208 Roundtrip, found 5 days ago
$208
Roundtrip
found 5 days ago
Select United flight, departing Sun, Nov 9 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Thu, Nov 13, priced at $208 found 5 days ago
Sun, Nov 9 - Thu, Nov 13
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$219 Roundtrip, found 5 days ago
$219
Roundtrip
found 5 days ago
Select United flight, departing Sun, Nov 9 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Thu, Nov 13, priced at $219 found 5 days ago
Mon, Oct 6 - Wed, Oct 22
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$226 Roundtrip, found 2 days ago
$226
Roundtrip
found 2 days ago
Select United flight, departing Mon, Oct 6 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Wed, Oct 22, priced at $226 found 2 days ago

Frequently asked questions

What route does flight number UA2021 take?
Flight number UA2021 operates non-stop from Washington Dulles Intl. Airport (IAD) to Luis Munoz Marin Intl. Airport (SJU). During this journey, expect to be in the air for roughly 3 hours and 48 minutes. It pays to book ahead to get your favorite seat.
How often is UA2021 on time?
United Airlines flight number UA2021 between Washington Dulles Intl. Airport (IAD) and SJU takes off according to schedule 81% of the time — so you can relax with confidence knowing that you will reach your destination ASAP. If this service is late, the average wait time is 18 minutes. This route has a 2.75-star rating.
What kind of plane is on flight number UA2021?
Chances are you'll find yourself on the Boeing 737-900 if your flight number is UA2021. Typically, this flight departs from Washington Dulles Intl. Airport (IAD) and touches down at Isla Verde Intl. Airport.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA2021 flight with Travelocity, please visit our Customer Service Portal.