Check the current status of aircraft reconfigured (or delivered) with new Polaris seats: http://view.ceros.com/united/polaris...-desktop-4/p/3.

A Polaris Update and Polaris Mod Schedule to indicate the status of specific aircraft are maintained by those that manage the United Airlines Fleet Website.

Except for 773- and 781-operated flights, and those markets selling Premium Plus, Polaris-equipped planes have not been allocated to specific routes. You won't know until approx. 36-48 hours before departure if you'll have a newly reconfigured aircraft, and even then, it may be replaced with a non-retrofitted aircraft.

777-300ER - All 22 aircraft have Polaris (60 seats) and installation of Premium Plus cabins (24 seats) is complete.

767-300ER - As of September 2020, 31 of the 38 aircraft have been reconfigured with the Polaris seats.
- Retrofit is from 3-cabin to 2-cabin with direct-aisle-access seats. No 3-cabin 767s remain in service.
- 76A configuration is 30J/50Y+/134Y, total of 214; fleet to consist of 17 ships (former 3-cabin 767s).
- 76L configuration is 46J/22PE/47Y+/52Y; fleet to consist of 21 ships (18 former 2-cabin 76C and 3 used ships from Hawaiian).

767-400ER - [16 aircraft] None updated yet; modifications put on hold due to Covid-19.

777-200ER - As of September 2020, 46 of the 50 aircraft have been reconfigured with Polaris and Premium Plus seats.
- Configuration is 50 Polaris seats, 32 in the front cabin and 18 in the second cabin (behind 2L/R)
- Configuration is 10 across in economy, with 24 Premium Plus seats, 46 86 E+ seats and 156 E seats, with E+ in front economy cabin plus exit rows and bulkhead at 3L/R, i.e., almost the same as current pmCO planes, except with 4 seats in middle section.
- Seat map (v5) on united.com

787-8, 787-9 - As of November 2022, all 787-8/9 are converted or in mod. No chance of flying old configuration anymore.
- 788 configuration has 28 Polaris seats (20 in front cabin, 8 in rear mini-cabin), and 21 Premium Plus seats (2-3-2).
- 789 configuration has 48 Polaris seats (32 in front cabin, 16 in rear mini-cabin), and 21 Premium Plus seats (2-3-2).

787-10 - 13 787-10s have been delivered in 2020. All come with Polaris and Premium Plus cabins factory-installed. Another 19 should be added by 2024.

FAQ:
Q: Does a Polaris ticket mean the aircraft has the new Polaris seat?
A: No, Polaris is the label UA uses for long haul international business class. It is also the label UA uses for the new seats, so this does create some confusion.
All the 773s and 787-10s are 100% the new seat.
The rest of the long haul fleet in various stages of conversion, see http://view.ceros.com/united/polaris...-desktop-4/p/3

Q: How to tell if my aircraft is the new style Polaris seats?
A: If the unassigned business class section is showing orange seats or all the seats are side-by-side or there is a section for 4 adjacent seats in the middle, this is an old style lie-flat aircreaft
If the unassigned bussines class seats are dark blue seats or the all the seats appear to have direct aisle access, then you aircraft is the new Polaris seat.
You can also look at the FT maintained, United Fleet Site and crosscheck the tail number or check thePolaris Update tab

Q: How to tell if my aircraft has the new PremiumPlus (PP) / Premium Economy seats?
A: If the unassigned seats just behind business class are purple seats or the aircraft is 773 or 787-10, then yes. However, the purple color seat will only show on routes where PP is being sold.
Aircraft with PP seats are being used on some routes but are not being sold as PP. In those cases, the seats are considered to be a part of E+. In those cases, an indicator of PP sold as E+ will be if the first few rows of economy, there are just 2 seats on the sides (with the rest of E+ showing 3 seats).

Q: Will the aircraft I see at booking be the same configuration at flight time?
A: Unfortunately with the fleet in transit, aircraft swaps happen. UA tends to use placeholders until 2 days before travel and even after that last minute swaps do happen.

Q: My flight seat map shows 772 with polaris seats is it a retrofit?
A: Possibly. The flight status page shows the most accurate scheduled aircraft. If a 77W is swapped in, it will list the aircraft as 777-300ER. However, if the 772's seatmap shows blue rectangular boxes in the business class cabin instead of orange "pointy rounds", this would indicate that a retrofit aircraft has been swapped.

See also: United Future/Changed Routes w/ Polaris seats