United MileagePlus is dangling a 100% bonus on purchased miles through October 31, 2026. Log in, and the best targets see it drop the effective price to 1.88 cents per mile when buying in the 20,000–25,000 mile chunks that trigger the full bonus. That's the headline. The reality is more surgical.

United capped purchases hard this year: 50,000 miles (including bonus) every 90 days, 200,000 annually per account. The promo runs just over a week. If you're staring at a specific Polaris or partner award that pencils at this rate, move. Everyone else is funding United's balance sheet.

The Math on 1.88 Cents

At 1.88¢, a 100,000-mile business award to Asia costs you $1,880 out of pocket. A 80,000-mile one to Europe runs $1,504. Add taxes—usually $50–$250 depending on the carrier—and you're in real money.

Compare that to cash fares right now. New York to London business one-way hovers around $1,300–$2,000 in shoulder periods; Los Angeles to Tokyo similar in the $1,900–$3,000 range for decent dates. If your award is available at the low end of dynamic pricing (80k miles to Europe on a Star Alliance partner like Lufthansa or SWISS, 100k to Japan on ANA), you're beating cash. Barely.

But United's own Polaris flights often price dynamically well above those saver levels. We've seen 120k+ miles one-way to Europe on peak dates. At 1.88¢ that's over $2,250 before taxes. Cash wins. Partner sweet spots are where the value hides—if you can find them.

Transferable Points Reality Check

Chase Ultimate Rewards transfers to United at 1:1. Your Sapphire or Ink points are effectively worth 1.88¢ here only if you value them at exactly that. Most optimizers get 1.4–1.6¢ from other redemptions or partners. Buying United miles at this price only makes sense when the specific award beats transferring Chase and booking the same seat.

Amex Membership Rewards doesn't transfer directly to United. You'd route through Aeroplan, LifeMiles, or ANA instead. Those programs often price the same Star Alliance flights cheaper in points, especially with current transfer bonuses floating around. Your math changes fast when a 25% bonus to Flying Blue or Aeroplan lands.

Bottom line: transferable currencies remain the smarter default. United miles are for when you need the exact routing, date, or cabin that only MileagePlus unlocks.

Polaris and Partner Sweet Spots That Might Pencil

Current saver-level clusters (post-2025 adjustments): Star Alliance partner business to Europe often lands around 80,000 miles one-way. To North Asia (ANA, EVA) closer to 100,000. These are the ones to hunt.

A 80k-mile Lufthansa business from Chicago to Frankfurt at 1.88¢ costs $1,504. Cash equivalent frequently exceeds $2,000 one-way in business. That's a win—if availability exists. Same for SFO to NRT on ANA at 100k miles: $1,880 all-in beats many $2,500+ cash fares when the product is The Room or similar.

The Excursionist Perk? It's effectively dead for new bookings. The old free intra-Europe or Asia segment on a round-trip is no longer reliable. That removes one of the program's historic multipliers. Your purchased miles now have to work harder on straight redemptions.

Dynamic pricing on United metal remains the wildcard. One day it's 65k to Europe. The next it's 150k. Speculative buyers are gambling that their future self finds a deal worth more than 1.88¢. History says most won't.

Who Should Actually Buy

Buy if you have a specific itinerary locked in your calendar with award space already showing at or below these levels. Buy for family members if their accounts show the 100% tier. Buy small—hit the 20k–25k bonus thresholds, don't max the annual cap unless the redemption is certain.

Skip if you're topping off an account "just in case" or hoping for a magical devaluation-proof sweet spot. United has been aggressive on award prices. The 1.88¢ price looks like a bargain until you realize the redemption value keeps sliding.

Check your targeted offer immediately. Different accounts see 75%, 95%, or 100%. The 100% version is the only one that gets close to compelling. Log in, run your exact routes for March–June 2027 travel, and do the division yourself.

Action item: Before the promo dies on October 31, search your precise dates and cabins on united.com. Calculate total miles plus taxes, divide by 1.88, and compare to cash or a Chase transfer. If it beats both, pull the trigger. Otherwise, let someone else subsidize United's next earnings call.