Why does this lounge have its own thread?
Unlike most non–United Club Star Alliance (*A) lounges in the United States, the Lufthansa lounge at IAD is physically accessible to domestic UA passengers. This means:

1. United *G members may access the lounge on domestic itineraries, even though they wouldn't be allowed free access to the United Clubs on such itineraries.
2. Passengers who otherwise have United Club access, whether due to a paid membership, premium cabin ticket, or a foreign *G card, have a nicer option in IAD.

What is the Lufthansa Lounge at IAD like?
There are two floors to the lounge: the concourse level, where you enter and check in, which also has the Senator lounge with ample windows; and the lower level, which has the Business lounge and showers. (The showers are very nice; on par with Senator lounge showers in Lufthansa's Frankfurt hub.)

The Senator lounge offers a complimentary buffet throughout the day. In the morning, there's a continental breakfast; at 1:30 p.m., they put out a hot buffet. Bottled beer and wine (including champagne) are available all day, with draught beer and spirits additionally available after 1 p.m.

[Need description of FTL offering. Include photos?]

How do I get there?
The lounge is located at the center of the B concourse, from where non-US airlines depart, to the right of the Aerotrain escalators as you enter the concourse from the train.

Hours have changed seasonally, but, as of June 2015, are 8:20 to 22:00. Some report the lounge opening earlier on occasion and some report it closing earlier on occasion.

From TSA/check-in, the B concourse is one stop away by Aerotrain, but in the opposite direction of the C concourse from where most United flights depart. When proceeding from the lounge to most UA flights, allow 20 minutes to get to the center of the C concourse, 25 if going to the far end of the D concourse.

To go to the C concourse, walk back to the Aerotrain stop and take it back to the main terminal; stay on it there and at the A concourse stop, then exit at the C stop. The walk from there to your gate may take more time than the rest of the commute.

To get to the D concourse if you're traveling light (or if you need to walk off the food you just ate), stroll briskly all the way down the B concourse and then go up the skybridge over to the A concourse. Bear right as you get off the stairs or escalators and you'll be at the mobile-lounge stop. Take that to the D concourse; enjoy the view of airplanes along the way.

Weighed down by luggage? Take the Aerotrain back to the main terminal, then head upstairs and take a mobile lounge to the D concourse.

How do I get inside?
With...

• Any Star Gold (*G) card (including UA Premier Gold and higher) and a same-day departing *A boarding pass in any class to any destination, domestic or international. There are reports (April 2014) that the physical card is no longer necessary; a *G designation on the boarding pass reflected in the barcode may be sufficient. (Senator lounge, 1 guest)
• A LH/LX HON/SEN card and a same-day departing or arriving *A boarding pass to/from any destination, domestic or international. (Senator lounge, 1 guest [plus spouse if HON] plus children under 18)
• A LH/LX FTL card and a same-day departing *A boarding pass in any class to any destination, domestic or international. (Business lounge, no guests)
• A LH Premium Economy boarding pass with ($35 adult/$20 2-12yo child) lounge pass purchased at the ticket counter. [Can it be paid at the entrance?] (Business lounge, no guests)
• A United Club or Maple Leaf Lounge Worldwide membership card and a same-day departing *A boarding pass in any class to any destination, domestic or international. (Business lounge, 1 guest)
• A same-day international departing *A First (Senator lounge, 1 guest) or Business (Business lounge, no guests) boarding pass
• A same-day arriving LH/LX First boarding pass. (Senator lounge, 1 guest)

In all cases, each guest must also present a same-day *A boarding pass for admission.

Lounge access for travel in a domestic premium cabin is not regulated by *A; as such, UA F domestic passengers (without other credentials) do not have access to the LH Lounge according to *A.com, just as they do not have access to the United Clubs. However, the international requirement for C/F tickets is conspicuously absent from Lufthansa's own lounge access sheet (see below), and domestic UA F passengers have reported admission. (Senator lounge, 1 guest)
[If we get (semi-)official confirmation of this policy, we'll add this to the bullets.]

Provided the lounge does not get overcrowded, as is often the case on US-based LH lounges, you may exit and re-enter the lounge as often as you wish. Note that if you are entering on a lounge pass, re-entry might not be allowed.

If your access question wasn't addressed by the above, first check the *A access policy and LH's official access policy, generally relying on the least restrictive policy of the two if they appear to conflict. If they answer a question that this wiki couldn't, update this wiki to help others! And if they don't, ask in the thread!

So, can I use the lounge upon arrival in IAD?
Only LH/LX SEN/HON (on any *A carrier) and LH/LX F passengers have access to the lounge upon arrival at IAD without regard to onward travel. See the list above for more details. There are reports, however, of passengers not meeting this criteria presenting their arriving boarding pass and still being admitted.

If you are connecting from an international flight in business class to a flight in economy and do not otherwise have lounge access, you might choose to fly United on your international segment, instead of another carrier, as United will admit its own arriving international BusinessFirst passengers to its United Clubs without regard to onward travel. If this is MileagePlus award travel, and the onward segment is on United and in economy because of a lack of award availability, you may also want to consider waitlisting for business class.

Furthermore, note that international passengers whose journey ends at IAD will be ferried by mobile lounge to the International Arrivals Building, which deposits passengers landside, to claim their bags and clear customs. [Can pax without checked bags choose to clear CBP in concourse C regardless?]

How does the Senator lounge compare to the newest Senator lounges in FRA?
Not favorably. The Senator lounge is like the old FRA lounges: cramped, and before a LH flight departure, crowded. There is a seating area set aside for first class passengers, which is less crowded. Perhaps due to the crowding, LH offers its departing F pax preboarding from the Senator lounge, something which the FRA/MUC FCT/FCL does not offer but is common among LH's outstation lounges. So, enjoying champagne and macadamias at the nose or upper deck while waiting is a nice feature of the IAD Senator lounge. [Still true?]

How does it compare to the United Clubs?
[Somebody write a succinct answer to this. Please discuss SEN vs. FTL areas, too, or at least mention if there's no difference anymore.]

How does the Senator lounge compare to the United GFL?
Apparently the GFL now has better champagne and food than the Senator lounge. However, there may be superior, "first class" champagne available for visitors traveling in first class. [Somebody please write more about this.]

This sounds too good to be true!
Lufthansa agrees! There were rumors that, effective January 1, 2015, LH's Business Lounges would become its *G lounges, which would mean non-LH *Gs would be directed downstairs to the Business lounge after that date; as of May 2015, however, this has not happened. There was some discussion of exceptions, most notable being that *G traveling in longhaul business class would still be admitted to the SEN lounge.

Lufthansa has been more generous than most *A airlines in admitting *Gs to its designated *A First class lounges—not even UA's own 1Ks get to visit United's first class lounges without a first class ticket—so this change would have brought Lufthansa somewhat more in line with the rest of the alliance.

Original thread: Consolidated "Access to Lufthansa Lounge at IAD" Thread [Merged]