Lounge Access for Award Flight that Starts in Economy and Continues on to First Class
 

I'm thinking of booking a MileagePlus first class award from LAX to NRT that shows an Economy on United Airlines from LAX to SFO and then First Class on ANA from SFO to NRT.

Will I be allowed any Star Alliance lounge access at LAX (such as at the UA Polaris lounge)?

I know that I'll get first-class lounge access at SFO but since the connection is only about an hour or so, I probably won't take advantage of it.

Thanks.

Very unlikely, unfortunately. If it were a UA flight to SFO-NRT then you'd get United Club access at LAX and Polaris Lounge at SFO (not *A lounge at LAX), however since your only international premium cabin segment is on NH, then United Club doesn't extend you that benefit at LAX. Star Alliance flights only give lounge access at the actual departure airport for your international premium cabin flight, so SFO in your case (which isn't a First Class lounge anymore, it's just the Polaris lounge now). If you had Star Alliance gold status, then that makes a difference, then you'd be eligible in LAX as well.

Typically the only way you are offered same day lounge at airports with an economy class departure is if you have Star Alliance Gold or depending on the carrier, if your premium cabin connection is on the same carrier (UA to UA for example). Also of note, in your situation, without Star Aliance Gold, it actually doesn't matter if you are seated in economy or domestic first from LAX-SFO, since domestic first on UA does not afford lounge benefits like it would in many other countries.

If you do book the itinerary you mentioned, and if you're willing to pay a change fee (assuming you're not Premier Platinum or higher), then keep an eye on ANA in the 2 weeks prior to departure, especially within the week of departure. They are pretty good about releasing 1 or 2 F seats at the last minute for mileage redemption, so you might be able to switch to the direct LAX-TYO flight, also giving you access to the *A lounge at LAX. Another one that you might look out for since you're planning to make a connection anyway is the Asiana (OZ) flight LAX-ICN with a connecting to NRT/HND. They are phasing out F on the A380 in the fall and it's an awesome seat. Some people say that OZ's F service is less refined than NH's but I have flown it and really enjoyed it. OZ has in the past been fairly generous with award availability in F.

Thanks dvs7310. I'll hold out for the direct flight from LAX to NRT.

They currently have 3 flights a day on the LAX route, so your chances are good. The two to Narita depart LAX noon-ish and there is one to Haneda around 1am.

There is no "first class" lounge at SFO. You would have access to the Polaris lounge at SFO on this itinerary, nothing at LAX.

You would be better off with a nonstop itinerary from LAX due to risk of delays into SFO.