United Flight 5221 Deals & Information (2025/2026)

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United Flight 5221 Route Deals From $145

The cheapest prices found with in the last 7 days for return flights were $191 and $145 for one-way flights to Denver Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Fri, Aug 22 - Sun, Aug 24
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$191 Roundtrip, found 4 days ago
$191
Roundtrip
found 4 days ago
Select United flight, departing Fri, Aug 22 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Aug 24, priced at $191 found 4 days ago
Fri, Oct 17 - Sun, Oct 19
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$219 Roundtrip, found 2 hours ago
$219
Roundtrip
found 2 hours ago
Select United flight, departing Fri, Oct 17 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Oct 19, priced at $219 found 2 hours ago
Fri, Aug 22 - Sun, Aug 24
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$221 Roundtrip, found 4 days ago
$221
Roundtrip
found 4 days ago
Select United flight, departing Fri, Aug 22 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Aug 24, priced at $221 found 4 days ago
Wed, Oct 15 - Sun, Oct 19
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$224 Roundtrip, found 2 hours ago
$224
Roundtrip
found 2 hours ago
Select United flight, departing Wed, Oct 15 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Oct 19, priced at $224 found 2 hours ago
Fri, Aug 22 - Sun, Aug 24
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$251 Roundtrip, found 4 days ago
$251
Roundtrip
found 4 days ago
Select United flight, departing Fri, Aug 22 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Aug 24, priced at $251 found 4 days ago
Fri, Oct 17 - Sun, Oct 19
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$274 Roundtrip, found 2 hours ago
$274
Roundtrip
found 2 hours ago
Select United flight, departing Fri, Oct 17 from Rick Husband Amarillo Intl. to Denver Intl., returning Sun, Oct 19, priced at $274 found 2 hours ago
Wed, Oct 8 - Sat, Oct 11
AMA
Rick Husband Amarillo Intl.
DEN
Denver Intl.
$291 Roundtrip, found 1 hour ago
$291
Roundtrip
found 1 hour ago
Select United flight, departing Wed, Oct 8 from Rick Husband Amarillo Intl. to Denver Intl., returning Sat, Oct 11, priced at $291 found 1 hour ago

Frequently asked questions

What route does flight number UA5221 take?
UA5221 is used on a range of routes. Most often, UA5221 flies straight from Lambert Field to Denver, CO Airport (DEN-Denver Intl.). If that's your chosen flight path, you'll be airborne for 2 hours and 26 minutes.
What terminal does UA5221 fly out of?
If you're heading off from STL, you'll probably board the plane from Terminal 1. The most traveled route for flight number UA5221 is STL to DEN, which is a nonstop flight.
What kind of plane is on flight number UA5221?
It's highly likely you'll be enjoying the services of an Embraer 175 if you've reserved a seat on flight number UA5221 from St. Louis, MO Airport (STL-Lambert-St. Louis Intl.) to Denver, CO Airport (DEN-Denver Intl.). It's the most commonly used aircraft on this route.
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 UA5221 flight with Travelocity, please visit our Customer Service Portal.