You really don't have a problem here. What you need to do is simple.

But I'll explain why before

A US citizen DOES NOT NEED A VISA for tourist or business visits to Schengen so Karlson's answer is partly wrong.

You will be granted admission to the national territory of the Member State, AND to the Schengen 'area of freedom and security' simultaneously by just turning up. This is the same as a European citizen being admitted to the USA on a visa waiver, without the bureaucracy of ESTA or green W forms.

The maximum you can stay in the whole of Schengen is 90 days cumulatively in any 180 day period. So if you stay 30days in Poland, 30 days in France, 30 days in Germany, you are in some difficulty and have to leave the whole area.

Think of the Schengen Area as being the United States, and Poland as being say, Texas or California. However, Poland remains a nation state, while Texas and California stopped being countries in the 19th century. This means that it CAN have national bilateral rules. Say between Poland and Ukraine, This is potentially important which I'll get to shortly. So Karlson MAY be (partly) right as well.

The way this works is, that once you have been 90 days cumulatively in Poland, on the Schengen equivalent of a visa waiver (i.e. you just turned up and they let you in) you MUST leave the whole Schengen area and can't come back until your average time in all Schengen states has declined to less than 50% unless you get a visa (Schengen or national).

This can cause you unexpected problems. I presume what you are doing here, is an extended family or pleasure visit (since you can't work).

The information you have given may be right. But the implications of it may not be apparent, and you can fall foul of it with awkward consequences.

The Schengen Agreement contains provisions for national rules to be maintained on cross border traffic between Schengen States and third countries with which those states share a land border. (If you need a reference I could probably find authority with a bit of research.)

So its theoretically possible that you might be able to do a day trip across what in European Law is called the External Border and Poland will let you back in (remember, you don't need a visa). But, IF it decides to do so (and it may not, border guards can be arbitrary), it's doing this under National (Member State) rules, and not under Schengen rules. So guess what, even though you are in Polish territory, you may not leave Poland across the (unmanned) State Lines for the rest of your stay without the risk of, (e.g. if in Germany and stopped for a minor traffic infraction) being held, and possibly deported to the USA for exceeding your 90/180 quota.

So what you do is this.

You arrive in Poland, without a visa. Once you've settled in and got over your jet lag, you go to the Town Hall and tell them you want a temporary residence permission that exceeds the 90 days you are allowed under visa-free entry.

There'll be a bunch of form filling, checking of passports, but provided you can prove you are able to support yourself without working illegally, and you have someone with you who speaks fluent Polish (preferably a local resident of the town concerned) you will get in due course, legal temporary resident papers.

With those, you can freely travel anywhere in Schengen for the whol of your stay.

But questions like this need proper research as the rules can change.

Today I called the Wielkopolska Voivodship Office Poznan to ask information about an extension of my visa because in a few days I get to the 90 days limit of my stay in Europe. I wanted to ask for an extension so I could have more time to get a student visa. The answer the woman gave me was the same as it is stated above; she told me I just have to travel outside Poland for one day, and she even went as far as suggesting going to Germany. I asked if she was really sure of this! and she said she was very sure. When I asked if I needed to try to get a stamp on my passport from the country I was visiting, she said that as that is not done in the border anymore I just needed any proof that I was outside Poland, like a receipt from a purchase... This got me very confused, it sounds too good to be truth, but now trying to get information about this I find this page... I don't know what to think, I talked with the office that is in charge of this visa extensions... I was very clear about the end of the 90 days, and she told me USA citizens don't have to worry about it as long as they get out of Poland to any country at least one day before the 90 days (in Poland) finish...

I also found this documented on the Polish embassy website in the visa section.

http://www.waszyngton.msz.gov.pl/en/waszyngton_us_a_en_consular_information_2/waszyngton_us_a_en_visas/

Based on an exchange of diplomatic notes between Poland and the USA, since April 15th, 1991 the US citizens are allowed to enter Poland for any 90 days period without visa.

And it specifically mentions the contradiction with the Schengen rules.

The common rule 90 days of stay in 180-day period does not apply in this case. Please note that the common rule is applicable for other Schengen States, and if its a consecutive trip to Poland you must cross the Polish border directly from the third country (non-Schengen State) e.g. direct flights from Chicago, New York, London, Moscow, Kiev etc.

Not sure this qualifies as official documentation of the rule, but made me feel a little more secure seeing it an official place.

I noticed that this older set of answers could use the following updated information regarding the US/Polish agreement. The agreement made in April 1991 which allows US Nationals, or legal residents, to remain in Poland up to 90 days at any time has been moved to a new location online. I tracked it down because I wanted a copy for use at the border crossing in Poland.

The original provided download link no longer works. Use the following link to download the bilateral Polish/US agreement document.

https://traktaty.msz.gov.pl/getFile.php?action=getfile;0&iddok=8047

Alternatively you can search for the document by date here: https://traktaty.msz.gov.pl  (You have to select United States of America, and then use the date of April 15th 1991.)

Based on this agreement US nationals can enter Poland for up to 90 days at any time. No need to wait for 90 days between visits. However, traveling in the Schengen zone on a passport is a sticky issue with no clear answer since border crossing officials can be fickle. As a result I would treat the rest of the Schengen zone (besides Poland and Denmark who also have similar arrangements with the US) as off-limits. They will likely treat your stay in Poland as counting against your time in the Schengen zone and thus visiting, for example, Germany while staying in Poland for more than 90 days in a 180 period can get you in trouble. However, I've never been asked for my passport while traveling between Poland and Germany by bus, or train. It's one of those things you would almost certainly get away with, but the consequences could be disastrous for you. So it's best to get a longer term Visa immediately after arriving in Poland.

I'm not sure if most readers on this thread follow Poland in the news, but they just refused their "allotment" of Muslim immigrants the EU dictated they take in. They [along with Lithuania] also grant the vast majority of Schengen visas to Belarus, who would otherwise have difficulty getting into Europe They also have major streets named after both Woodrow Wilson and FDR in Poland, and consider themselves proud that they have a "Special status" regarding relations with Washington D.C. - I've traveled all over and nowhere treats Americans as Warmly, on the whole as does Poland - when Passport liens have been slow coming into Warsaw from Moscow, I've held up my American blue passport and within a minute had a special line open, been called over to it, and immediately whisked through while the rest of the travelers endure scrutiny. This extends to coat checks in crowded concerts - from top to bottom, Americans are shows favoritism - often above their own citizens - THAT BEING SAID - it is important to understand that Poland is part of the Schengen ?on? - so exiting another European country after staying in Poland for a long time could create "issues" - quite frankly, if you want to leave for "home" there's really nothing to be afraid of anywhere in the West - flying you home is the "worst case scenario" - personally I'd never give any government a nickel to leave their country - they don't want dyplomacy problems with America. THAT SAID - I would absolutely be respectful of Poland's hospitality and I would not overstay beyond 90 days without a formal visa - you can expect border guards to take their job seriously. Now that other nations won't stamp your passport, you can get away by printing up a German hotel, but Ukrain? is not an EU state AND does not require visas for U.S. Citizens - so, it's the ideal place to cross into. KEY POINTS TO BEWARE OF: Say you stay in Poland 18 months, going to Ukrain? every 80 days... THEN YOU FLY TO USA ... BECAUSE OF "BORDERLESS STATUS" OF EU IF YOU CONNECT WITHIN EU YOU MUST CLEAR IMMIGRATION IN THE COUNTRY YOU LEAVE EU FROM - This could be a huge pain in the ass if you expect to fly home out of, say... Germany (or any other Schengen ?on? state) , as you will have overstayed Schengen ?on? - you'll want to leave on LOT direct to JFK (or Chicago they might also go). It's generally not difficult to get a visa in any nation - the key to understand is you need a connection with a CORPORATION that will sponsor you. Governments want people who contribute to their economy.

I would suggest that you get a national long-stay visa, as this diplomatic note you were told of will hold no weight when you can't show proof of it, and in actuality what you are trying to do is considered to be fraudulent.

Border hopping to gain a new travel visa, while a blind eye may be turned, is a fraudulent act, in doing so you could cause yourself to incur a fine, or worse yet be deported as well as being placed in the schengen information system that could red flag you the next time you try to enter the schengen area legally.

Get a national visa from Poland and give up the search for the loopholes, thanks to the schengen agreement the old days of extended stay border hop travel through europe is declining rapidly.