United Flight UA2021 Deals & Information (2025/2026)

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United Flight 2021 Route Deals From $73

The cheapest prices found with in the last 7 days for return flights were $146 and $73 for one-way flights to Luis Munoz Marin Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Sat, Nov 8 - Wed, Nov 12
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$146 Roundtrip, found 19 hours ago
$146
Roundtrip
found 19 hours ago
Select United flight, departing Sat, Nov 8 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Wed, Nov 12, priced at $146 found 19 hours ago
Sun, Sep 21 - Tue, Sep 30
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$166 Roundtrip, found 3 days ago
$166
Roundtrip
found 3 days ago
Select United flight, departing Sun, Sep 21 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Tue, Sep 30, priced at $166 found 3 days ago
Sun, Oct 19 - Thu, Oct 23
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$192 Roundtrip, found 19 hours ago
$192
Roundtrip
found 19 hours ago
Select United flight, departing Sun, Oct 19 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Thu, Oct 23, priced at $192 found 19 hours ago
Sun, Sep 21 - Tue, Sep 30
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$211 Roundtrip, found 3 days ago
$211
Roundtrip
found 3 days ago
Select United flight, departing Sun, Sep 21 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Tue, Sep 30, priced at $211 found 3 days ago
Mon, Dec 8 - Tue, Dec 16
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$211 Roundtrip, found 5 days ago
$211
Roundtrip
found 5 days ago
Select United flight, departing Mon, Dec 8 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Tue, Dec 16, priced at $211 found 5 days ago
Mon, Dec 8 - Tue, Dec 16
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$216 Roundtrip, found 5 days ago
$216
Roundtrip
found 5 days ago
Select United flight, departing Mon, Dec 8 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Tue, Dec 16, priced at $216 found 5 days ago
Sun, Oct 19 - Sat, Oct 25
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$218 Roundtrip, found 5 days ago
$218
Roundtrip
found 5 days ago
Select United flight, departing Sun, Oct 19 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Sat, Oct 25, priced at $218 found 5 days ago
Tue, Sep 16 - Fri, Sep 19
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$228 Roundtrip, found 14 hours ago
$228
Roundtrip
found 14 hours ago
Select United flight, departing Tue, Sep 16 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Fri, Sep 19, priced at $228 found 14 hours ago
Sun, Oct 19 - Thu, Oct 23
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$230 Roundtrip, found 19 hours ago
$230
Roundtrip
found 19 hours ago
Select United flight, departing Sun, Oct 19 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Thu, Oct 23, priced at $230 found 19 hours ago
Tue, Sep 16 - Fri, Sep 19
IAD
Washington Dulles Intl.
SJU
Luis Munoz Marin Intl.
$235 Roundtrip, found 14 hours ago
$235
Roundtrip
found 14 hours ago
Select United flight, departing Tue, Sep 16 from Washington Dulles Intl. to Luis Munoz Marin Intl., returning Fri, Sep 19, priced at $235 found 14 hours 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.