As noted above, you can view all fare class availability by enabling Expert Mode. From there, you'd initiate a revenue search instead of selecting "Book with miles" on United's website.

Your United fare class will impact your ability to get upgrades and earn elite qualifying miles and segments. Many or all of the products on this page are from ...

United First is available on international short-haul and domestic flights, and it's typically not lie-flat seating. Many or all of the products on this page are from partners who compensate us ...

What you might not know is that it offers a unique feature where it reserves some flight award availability for certain customers. Just as United sells different cash fare levels (such as economy ...

Award flights can be booked online or via the United app; you can also call to book an award flight, though a fee applies. To find out how many miles are needed per flight and per seat class ...