As a (fully vaxxed) US citizen traveling in the EU with a flight out of Budapest to the US, can I fly into BUD from a Schengen country and transit out of BUD? Say Madrid to BUD then (on a Different ticket) BUD to Miami without leaving the airport?

I know we can't enter hungry as US citizens (by air at least), but hoping overnight transit via 2 different airlines is ok?

Alternatively, can I drive into Hungary from Serbia (US citizen) and then fly out of Budapest?

Check here: https://www.iatatravelcentre.com/int...1580226297.htm

When you are moving around on separate tickets, the airlines are generally going to deny boarding unless you have the right to enter the country in question. Especially if you are wanting to overnight in country (even if it's airside at the airport)

Also note that residence and your location during the prior 10-14 days is usually what matters, not your passport. So if you've been in Spain long enough, you would be subject to the rules for travel between Spain and Hungary, not the US... Even if Hungary didn't accept your CDC card as proof of vaccination (I have no idea of the current rules for Hungary), you might still be able to travel with a PCR or antigen test.

P.S. FWIW you should not be doing multi-country tours of Europe at the moment. Too many moving pieces with restrictions and requirements...

THIS

When are you considering OP ?

Delta will likely sweep Europe, some countries worse than others, so borders / rules / restrictions will change a lot - at short notice. Keep everything very simple and don't plan too far ahead

According to police.hu info updated 22/July

Information on general rules of border crossing | A Magyar Rend?rs�g hivatalos honlapja

Read on the article for rules on air travel.

Accordingly, "Alternatively, can I drive into Hungary from Serbia (US citizen) and then fly out of Budapest?" seems to be doable.

This would be flying out of BUD first week in Sept.

And agreed, I'd prefer not to take this trip, all things equal. This is a Delta/KLM error fare booked at the beginning of Covid that's been pushed out twice. Getting a refund/credit is a last resort, but complicated. We fly in on AA into madrid mid-august (BE ticket upgraded to J via SWU), then out of BUD in J on the error fare.

Thanks. That's how I read it as well. However later in the same doc it states:Foreign citizens arriving from abroad in passenger traffic � unless otherwise specified by law or government decree � shall not enter Hungary.

So I was confused about which contradiction is correct.

I think your biggest problem would be getting on the flight as the rules are not clear and enforcement is a bit chaotic. Your best bet would probably be to fly to Vienna and take the train to BUD. Currently there is no border control and Austria has been pretty consistent with its rules throughout the pandemic. Of course both might change if the situation gets worse in Austria.

Burocratese...

My reading is that in general foreign citizens are not allowed to enter, EXCEPT (cue in all the exceptions about land borders, vaccinations, etc) which are the "otherwise specified" bit.

Not sure if this is still helpful, but I recently flew IST-BUD-FRA-DEN. US Citizen, fully vaxxed. Was able to "transit" in BUD (though, it did confuse the gate agent in BUD and passport control in FRA). Not sure if I got lucky. Passport control at BUD gave me an entry and exit stamp together.

That's odd, since you did not exit Schengen there. Did you get another exit stamp in FRA?

Update: We successfully entered hungary by train from vienna. No passport control between countries via train. Departure from BUD by air was also uneventful.