From another thread:

Any data points as to whether or not LAX accepts walk ins? I couldn't find any recent posts since they have doubled their staff/offices. Will be connecting at LAX with 5 hours to kill before our international flight and thought I might give it a shot if I get conditional approval beforehand (not holding my breath - it's been 2 1/2 months since applying). Wife already has conditional approval and has interview scheduled in late March but will do enrollment on entry if nothing else......

Also, according to the CBP website the LAX office is on La Cienega - so is it not accessible from the terminals without taking a cab ride?

Anyone have any success with walk-ins at MSP? We only have one location here. Thought I'd check.

Just taking a shot in the dark to see if anyone has had an experience at MCI since this was posted a couple of years ago?

put in my application several weeks ago and still haven't been conditionally approved for an appointment. My PreCheck runs out sooner than the next available Global Entry appointment on the website for MCI. (Of course I'm kicking myself that I was in Chicago last week and forgot to try a walk-in there.)

Has anyone been able to successfully walk-in for a Milwaukee appointment?

SEA - Seattle-Tacoma Int'l Airoport (Seatac) - Mezzanine Level, Room MT6439M
Yes [30min] (6/17/2019 at 1:15pm, w/3 family members) "Sorry we have to be fair to people with appointments, you have to wait until no one is waiting for their appointments, it could take an entire day"

I had 3 family members with appointments, I did not. Fortunately I booked the family members at 13:15, 13:30, 13:45. They took them all at once and after 30min there was no one left waiting so they took me in.

Confirming walk-in is available at the Ronald Reagan Building in Washington DC as of July 2019. I arrived at open (7 AM) and there were 2 people ahead of me and I was gone by 7:30.

I live in northern VA and there were no appointments around me projected through the end of time. The closest was Newark. During my interview I commented that they must be slammed with appointments filled up through the projected 6-month scheduling period. The CBP agent said no, they typically have several times a day with no one in the office. He was unaware that there is a scheduling system on-line, he thought it was all jut walk-in. He also said he was on loan from another state and didn't know who to tell about the scheduling system on-line showing no appointments. Your gov at work...

So just a heads up, in the general DC area, it seems the CBP site has a disconnect and your only real choice is to go downtown DC as a walk in as Dulles (IAD) also has no appointments but does not take walk-ins.

Can't add my DP to the wiki at top (perhaps someone else can?) but my young son and I successfully completed our interviews at Hartford-Bradley BDL last week as walk ins (neither of us had appointments). There were two people waiting ahead of us when we got there around 2:30pm on a Weds, both with appointments. We went after them, total waiting time for us maybe 15 minutes. Our interviews took about 5-10 minutes combined, and when we left no one else was in the waiting area. The officer was really nice and efficient and not at all put off by us being walk-ins. There is free and convenient parking right by the building too.

Moderator's Note
 

I have added the last two data points to the wiki.

It would help to know the date or day of the week of the walk-in interviews and the wait time.

Thank you,

TWA884
Travel Safety/Security co-moderator

We attempted a walk-in at MSP on July 5th, around 1:00 pm. It was not successful. There was a sign on the door saying interviews were in progress and and not to knock on the door. We waited there for an hour and didn't see one person enter or exit the GE interview room, so I think that there was just no one there. It does look like MSP is only scheduling interviews from 9-12 M-F, so if you're going to try walking in, maybe attempt it during those hours only.

If you're near DC you can do a walk-in appointment at the enrollment center in the Ronald Reagan Building downtown if you want to take care of it ahead of time.

Has anyone set their interview appointment and then just showed up days/weeks before the appointment and been able to get their interview there on the spot? I'm currently at day 123 waiting for CA. I have a feeling I may be approved soon, but I bet the available appointment slots are months ahead for DFW. I'll post my final CA date once received. Thanks!

Really? I saw that as a location when scheduling the appointment but it said none available. I didn’t know that was walk in only. Any idea where i can find more about this?

Most sites are very strict and will turn you away if you try for an unscheduled walk-in interview. If you search around, you may find some more lenient sites, but YMMV. Probably depends on the agent on duty that day.