Low-cost airfare is back: Fly from $21 on full-service carriers into 2021

As the travel industry reopens following COVID-19 shutdowns, TPG suggests that you talk to your doctor, follow health officials' guidance and research local travel restrictions before booking that next trip. We will be here to help you prepare, whether it is next month or next year.

Low-cost airfare is officially back.

We saw this coming with the recent Alaska Airlines buy one, get one sale, and United award tickets selling from 5,000 miles each way.

Though we're still in the midst of a pandemic, with masks required on all U.S. airlines and quarantines still in effect when entering many states, several domestic airlines are clearly ready to try and stimulate demand the old fashioned way with cheap airfare.

How cheap, you ask? We're talking $21 from New York to Florida on a full-service airline cheap, or $57 for a transcontinental flight on a low-cost airline. Seriously.

Related: What it's like to fly in the U.S. right now

There's certainly room for very reasonable debate about whether now is the best time for more travelers to leave home and take to the sky just because the tickets are cheap. But, with TSA screening numbers still generally trending upward week over week (reaching, so far, over 800,000 people daily), people are flying.

So, if you've decided to fly again, you might as well get the best deal you can.

Another upside of these unusually cheap tickets is that you don't have much money on the line if you need to ditch your travel plans at the last minute.

In many cases, the airlines are still allowing you to change your plans without penalty, but if you paid several hundred dollars for a ticket, that's still several hundred dollars you'll have tied up with the airline until you do ultimately fly. But if you only paid $21 for a ticket, that's a relatively inexpensive purchase if you change your mind.

Related: 5 tips for planning a trip during the ongoing pandemic

Here are some evergreen tips for finding the cheapest flights, but if you're curious about the low fares airlines are advertising right now, here's a sample of deals we've found well below normal prices. We mostly highlighted discounted basic economy fares on full-service carriers.

• Newark (EWR) to Fort Lauderdale (FLL): $21 one-way on United, dates into late January 2021
• Newark to Austin: $26 one-way on Spirit, dates into March 2021
• Chicago (ORD) to New York (LGA) $40 one-way on American or United, dates into February 2021
• Denver (DEN) to Chicago: $41 one-way on United or American, dates into February 2021 (tickets start at $20 on Frontier)
• Houston (IAH) to Newark: $43 one-way on United, dates into December
• Washington-Dulles (IAD) to Chicago: $49 one-way on United, dates into February 2021
• Los Angeles (LAX) to Austin (AUS): $50 one-way on United, American, and JetBlue dates into January 2021 (tickets start at $38 on Spirit)
• Dallas (DFW) to Orlando (MCO): $50 one-way on American, dates into December (tickets start at $24 on Frontier)
• Miami to Los Angeles: $57 one-way on American, dates into March 2021

Related: We compared pandemic-era flights on four airlines, here's what it was like

Bottom line

It's been a long time since there were so many opportunities to fly for around the cost of a meal at Applebees on carriers such as United and American.

Coincidentally (or not), these are the airlines not guaranteeing blocked middle seats. If you want to ensure you'll have that extra space, you may need to budget in the cost of buying a second seat, too.

Additional reporting by Andrew Kunesh