I booked a flight over the phone the other day and used PMUs to upgrade. I have confirmed fist class (G) for the flights. I noticed though that in between the flights at LAS there is only a 20min layover. I really don't think i'm going to make that and its the last flight of the day. I know they usually just book you on the next flight out but what happens with the PMU? Do I get a PMU reissued to me? Or is it gone forever? Or do they just rebook you into F? Thanks

If you have flown a segment to which the PMU was applied before the LAS segment, the PMU is gone.

You're entitled to the next seat in the purchased class of service. You can wait for a seat in First. Depending on time of day and what's going on in Vegas, that could be a long wait.

Yup, if you've already used the PMU for xxx-LAS and you mis the LAS-yyy then its gone since you already had a segment upgraded. However they should rebook you into F if you miss the flight, especially with that crappy connection. I'd even call and find our if they can protect you on the morning flight without touching your currently confirmed itinerary, just in case. I'm kind of surprised they allowed a 20 min connection... even though with LAS the Delta gates are in an area next very close to each other.

Sorry to hijack but this has raised a question in my mind. Is a PMU valid for ALL segments of each leg of a trip or do you need a new PMU for each segment?
Thanks!

Its valid for all segments of one leg... so a typical round trip would require two PMU/SWU.

Note there are some limits, such as a multicity trip with a stopover somewhere.

Just an update:
I called and they agreed with me that 20mins was a little ridiculous. I can see on my itineraries page that he has booked me on the next flight in the morning. I found it odd that he did that for me... in H class too.... The rest of my flights were purchased K and upgraded to G.

Do you still have your original flight confirmed as well in case you can make it?
It is strange that the next day is booked in H, unless the agent just grabbed H because it was the lowest one available without having to put in more effort. Kinda sucks they didn't protect you in full Y at least though so you get an upgrade, or even F due to your PMU usage if you misconnected.

Exactly how did you purchase a ticket with a twenty minute connection? This is clearly an illegal connection as it's less than minimal connecting time (anywhere, AFAIK) and in principle should not be bookable. The DL phone agent should have never sold you such a ticket.

However, to some extent, it's your responsibility too. Whenever I make a phone reservation, I always insist--it annoys some agents when I ask, but so what--that they tell me exactly when the first flight lands, the connecting airport, and when my next plane would depart for every itinerary that i'm seriously considering. Unless there's absolutely no other choice, I would never accept less than about forty-five minutes for a connection, more in some circumstances, some airports, some dates, some seasons, etc.

If the twenty minutes is the result of a schedule change or clear error by a DL agent, DL should make it right by rerouting/rescheduling you with upgraded seats, if necessary by opening up inventory IMO. You seem happy with the current solution, even though it probably means that you lose the upgrade and will have to pay for an additional hotel night, perhaps at a rack rate in Vegas because you won't be sure until you actually miss the connection. IMO, this is acceptable if the mistake was yours (or your living travel agent's), but otherwise not. If you can only get the upgrade for one of your two (?) segments in this direction, would you prefer to get your SWU back and lose the upgrade guarantee on the other segment? (If you were upgrading with miles, this would be easy--I've cancelled milage upgrades for no reason other than changing my mind and deciding to risk not getting an EUA--but if the ticket has already been reissued with the upgrades, the official rule is supposed to be no refunds of SWUs.) It might help to think of potential resolutions in terms of two separate issues: (1) fixing the ticket/itinerary (how can you get where you're going?) and (2) either using or refunding the SWU (remember, the SWU should either get you an upgrade that you can't get through EUA, i.e., TATL/TPAC or guarantee an upgrade for you on a flight that could otherwise be difficult to upgrade through the EUA process. If you're elite enough to get SWUs, they shouldn't be used for a domestic standby/battlefield upgrade because presumably if it clears, you also would have gotten the upgrade for free. The usual FT advice applies: figure out what you want, call, and if you don't like the answer, call again but be polite.

To me, it also seems very strange that DL would create a connection for you through a nonhub that I don't think is even a focus city for DL. (Have you experimented with trying to recreate your exact itinerary, perhaps for some different dates farther in the future, on delta.dumb? It tends to sometimes suggest some wierd routings, but I haven't seen such connecting times appear for a while on either paid or award tickets, although I did manage to generate a SLC connection with negative connecting time a few months ago.) Since LAS isn't normally a connection point for DL, there's a risk that if your incoming flight goes WX or MX and arrives very late, there could be no DL agents available to help you at LAS. It might also even be the case that the airport isn't set up to transfer bags to your next DL flight.

I didn't even think of asking what the connection time was, I just assumed it was legal. And yes, if you search for the same flights on delta.dumb it will give you the 20min connection. I think I should call again and see if there are any other options. Thanks

This is what my itinerary looks like right now btw:

Not to go off-topic, but there have been times and hubs where 20 minutes was in fact the domestic-domestic minimum connect time. (I'm recalling a few years ago at CVG, specifically.) It may still be today - it's plausible, though too risky for me - at MEM or SLC.

edit: I see the OP's LAX-LAS-SLC route is bookable today with the 20-min connection.

Delta operates ~45 flights a day at LAS. It's not some podunk outstation.

I know minimal connecting time in MEM is 25 minutes, which I thought was the minimum anywhere. It might be feasible there if one knows the airport, is seated in front, and knows that the far commuter gates aren't involved, but I still wouldn't be comfortable booking it if I had any other choice.