United Flight 400 Deals & Information (2025/2026)

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United Flight 400 Route Deals From $191

The cheapest prices found with in the last 7 days for return flights were $329 and $191 for one-way flights to Newark Liberty Intl. Airport for the period specified. Prices and availability are subject to change. Additional terms apply.

Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$329 Roundtrip, found 5 days ago
$329
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $329 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$339 Roundtrip, found 5 days ago
$339
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $339 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$419 Roundtrip, found 5 days ago
$419
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $419 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$429 Roundtrip, found 5 days ago
$429
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $429 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$451 Roundtrip, found 5 days ago
$451
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $451 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$458 Roundtrip, found 5 days ago
$458
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $458 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$461 Roundtrip, found 5 days ago
$461
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $461 found 5 days ago
Thu, Mar 13 - Tue, Mar 18
MTJ
Montrose Regional
EWR
Newark Liberty Intl. Airport
$468 Roundtrip, found 5 days ago
$468
Roundtrip
found 5 days ago
Select United flight, departing Thu, Mar 13 from Montrose Regional to Newark Liberty Intl. Airport, returning Tue, Mar 18, priced at $468 found 5 days ago

Frequently asked questions

What route does flight number UA400 take?
UA400 operates from Dulles Intl. Airport to Raleigh–Durham Airport and is a direct flight. This trip takes 1 hour and 11 minutes.
What kind of plane is on flight number UA400?
The route for flight number UA400 is generally Dulles Intl. Airport to RDU, and the Boeing 737-800 is the aircraft model you’ll probably be flying with.
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 UA400 flight with Travelocity, please visit our Customer Service Portal.