While there's so much to be said about this topic, I'm going to mention one specific incident that might illustrate some difficulties with reintegration that you might not be familiar with.

As you may know, pre-war Poland had a Jewish population around three and a half million. During the Holocaust around 98% of them were killed. Several thousand made it back to Poland afterwards, joining those few who had survived in place and those who had fled to Poland from genocide in other countries.

In July of 1946, just over a year since the end of the war, there were about 200 Jews who had returned home to the town of Kielce, Poland. Their former homes were no longer available -- a phrase that glosses over another injustice against them -- so most of them were staying in a building they had purchased for temporary housing.

A young boy from the community went missing for two days. When he turned up, he at first told his father that he had been kidnapped (though it turned out he had just been staying with another family). The community and local authorities decided that the Jews were to blame, and that they were kidnapping and murdering local children.

This kind of bizarre and unfounded accusation is a centuries-old conspiracy theory called blood libel that is still used to this day. Accusing your rivals of kidnapping and murdering children without any evidence sounds like an impossible slander that couldn't gain any traction. But this kind of accusation works. Some people will believe their enemies are capable of any crime, justifying any degree of cruelty in return as they imagine themselves to be defending children.

The local authorities in Kielce sent the militia to investigate. They broke into the Jewish housing and found that (of course) there were no abducted children there.

In any halfway-reasonable investigation, this should have been the end of it; they searched and found no evidence of the supposed crime. But I think their response to the lack of evidence is illustrative of the situation the Jews of Poland were in. The militia and the hundreds of people that had gathered outside started robbing, attacking, and murdering their Jewish neighbors. Many were dragged into the street and beaten to death, some were shot, some were stabbed with bayonets.

By the time soldiers arrived to put a stop to the massacre, 42 people had been killed and dozens more injured.

Then the wounded were attacked on their way to the hospital, then attacked at the hospital, then a lynch mob arrived to demand they be turned over, then people murdered several Jewish passengers on trains passing through... Over the next year, the majority of the surviving Jews in Poland fled the country.

To answer your question, in many places Jewish survivors of the Holocaust weren't allowed to reintegrate, as the genocide wasn't over.

We must start by the usual disclaimers of “this is not my area of expertise” and "excuse my English, it's not my first language". That said, I can answer part of it based on the experience of one Jewish survivor that I researched for a project.

Prisoners were liberated either in camps or in the middle of a death march, put in motion by the Nazi guards trying to escape the Allies and the Red Army. After years of abuse and famine, the first thing was to eat and that itself was a danger, because an emaciated body couldn’t handle big amounts of food right away. In the first months after the end of the war, everything was a mess and it was relatively easy to pass from one country to another, something that would change when the Iron Curtain became a reality. Survivors could find the Red Cross and identify themselves as survivors from the camps, and then were provided with an ID which granted them free pass so they could travel for free. Jewish institutions, in special the American Jewish Joint Distribution Committee (JDC), who raised funds for the survivors and their needs, were crucial to the resettlement of Jewish Refugees after the war. I’ll mention some of them along the text.

With this new passport, there was the issue of deciding where to go. A lot of them were aimless, not knowing what to do or where to go. Some may have known something about what happened to their families, either because members immigrated before the war or on its early stages, or because some news of their escape from Europe or their internment in camps somehow made their way to them. Many, though, were completely in the dark and absolutely hopeless. Antisemitism didn’t vanish in face of the horror, and it also wasn’t a Nazi creation of 1933. People who suffered it before and during the war did not want to return to their former homes, or even stay in Europe, remembering the atrocities and the hate. Most wanted to leave for America, mainly the US, but to other countries of the continent as well. However, visas were scarce and many countries had restrictions in place against and would not issue visas for Jewish immigrants for quite some time after the war. Without visas and without homes, Jewish survivors were largely unwanted and their numbers was a problem.

Before the end of the war, discussions about how to liberate, rehabilitate and repatriate the millions of people displaced through the continent were already taking place. Another type of camp was created, for these Displaced Persons (DPs), and the army would be responsible for the immediate relief under the United Nations Relief and Rehabilitation Administration-UNRRA, in hopes that they would choose to go back to their former homes. According to the UN archives, UNRRA “was established by agreement of 44 nations on 9 November 1943; operations came to an end in the latter part of 1946, with the last staff appointment terminating 31 March 1949. The purpose of UNRRA was to 'plan, co-ordinate, administer or arrange for the administration of measures for the relief of victims of war in any area under the control of any of the United Nations through the provision of food, fuel, clothing, shelter and other basic necessities, medical and other essential services'” (Agreement, Articles 1 and 2)[1].

In these camps, a document was issued with their data, name, age, home town, etc., and tracing of survivors began right away. Although millions died, even in these early stages it was possible to find a lost family member with the help of Jewish Committees stablished in the places where Jewish people began to settle. Millions of people were in fact repatriated, but around 1 million, mostly from Eastern Europe and half of them Jewish, didn’t have anywhere to go. Jewish Displaced Persons, the Remaining Survivors (Sh'erit ha-Pletah), became long term residents of the camps and suffered a less than ideal treatment in them. With the help of the JDC and the Jewish Relief Unit (JRU), services were created to help tracing survivors, get educational and religious supplies, promote events and professional training to help integrate them into the work force. In the camps, people would sleep in communal tents or, in places Lampertheim[2], a camp founded in December of 1945 that housed around 1200 Jewish persons between 1946 and 1947, Germans would be expelled from their own homes in favor of a survivor, which obviously became a huge problem and conflicts arose many times between them, fueling the wish to leave and find a new home. With the lack of jobs, some people got into a black market, selling American army supplies, mostly food, to German citizens.

Still figuring out their lives, others went back home. In the case of Poland, the one I’m familiar with, small Jewish communities were formed, organized around Jewish Committees that would help find a place to stay, food and work. Polish towns, devastated by war, had many empty houses, so it was possible for survivors to just occupy these houses and furnish them with whatever they found. To look for their families, they had help from the Jewish Committee, the JDC and would also travel to DP camps when they got news about someone. The survivor I researched managed to find his brother and cousins, all of them survivors. He also got married to another survivor who herself found her brothers not long after the war. Jewish agencies would carry on looking for survivors to reunite with their relatives for many years, using the Jewish press to call for missing people.

An option presented itself with the possibility of Israel: a Jewish state where they wouldn’t be persecuted or denied entry. Jewish settlement in Palestine, the kibbutzim, in the hopes of the creation of a Jewish state wasn’t knew. After the war, the Jewish Agency for Palestine sent envoys (shelichim) from these communities to Europe in search of survivals who wanted do immigrate to Israel and strengthen Jewish presence there. These envoys would encourage them to learn Hebrew and make presentations about the need for their own state while they waited for a way out of Europe. It wasn’t an easy journey due to the visa situation and, at the same time, the UK, who controlled Palestine, restricted immigration, so in a lot of cases it was necessary to enter the country illegally. The journey became even harder with the Iron Curtain and access to ports in West Germany and Italy became harder. An option was to falsify documents, pretending to be people in need of repatriation. The envoys would arrange the documents, help organizing the trip, give instructions on how to behave, arranging settlement along the route with the JDC, bribing officers on borders, etc.

Once in Palestine, life wasn’t easy. Another war began, involving the British, the Jewish and the Arabs what again meant lack of food, fear, and actual danger. After official acts in 1948 and 1950 in Europe, many DPs immigrated to Israel and all those problems were heightened by the situation of Israel as a new country with little infrastructure, in a deserted land and full of immigrants who didn’t know how to live in those conditions. In the early 1950s, although most remained, many people had returned illegally to Europe, called the returnees, where they could more easily obtain a visa for America with the help of the JDC and the Hebrew Immigrant Aid Society (HIAS). Around 1952 and 1953, around 43 thousand people left Israel to Europe.

The last DP camp in Europe, Fohrenwald, near Munich, was still functioning in 1953. With the rising number of people returning, the camp was closed for new arivals in October of 1958, so in November there were three categories of Jewish refugees in Germany: legal (who had not gone to Israel); semi-legal (returnees registered until August); and illegal (those returned after that date). Some returnees who didn’t make it to Germany remained in Paris and Wien, and I don’t know anything about their situation. After a conflict with these illegal refugees and the German police in October of 1953, a negotiation was undertaken between the Army and diplomatic representatives. Norway, Belgium and Brazil, who had recently lifted restriction on Jewish immigration, received hundreds of them, who could then restart their life, hopefully for good.

My main source here is the survival account of Arie Yaari, “O Leão da Montanha (The Lion of the Mountain)” who was sent to a labor camp at age 18, survived 11 camps in the following years, was liberated by the Red Army, almost died from the hunger and from the food intake afterwards, got married in a DP camp, immigrated to Israel, returned to Europe and was arrested in 1953 for being an illegal immigrant in Germany. He found a new home in Brazil, divorced, remarried, had 3 kids, 10 grandchildren, 15 grand-grandchildren, and died in 2010, at 88 years old.

[1] https://search.archives.un.org/downloads/united-nations-relief-and-rehabilitation-administration-unrra-1943-1946.pdf

[2] https://encyclopedia.ushmm.org/content/en/article/lampertheim-displaced-persons-camp

I'm surprised to see the only past answer I can find about this is this one from ten years ago! However, it contains lengthy, quality answers from /u/angelsil and /u/eternalkerri.

Not an expert etc, but I have read a couple of books on the subject. In Göran Rosenbergs "A brief stop on the road from Auschwitz" Rosenberg tells the story of his father David Rosenberg, a polish jew who grew up in Łódź and is eventually brouth to Auschwitz to die, but is saved by the Germans' need for slave labour. As the war drew to an end, David is one of about 9000 people who are aided by the white buses, a humanitarian expedition organized by the Swedish government.

David is brought to Sweden and ends up in a small flat in the town of Södertälje, just south of Stockholm. Having been forced to work as a slave in the German industry, he is now able to use his aquired skills in the booming Swedish auto industry. He also manages to reconnect with an old friend who also miraculously survived. They get married and start a family, life is looking up.

David is still haunted by his experiences in Auschwitz however, as the years pass the darkness grows within him. After an antisemitic insult at work leads to a fight, he decides to quit his job. He tries the role as a travelling salesman but is not very successful. In the late 50s, as part of the post war demands on the Germans, the allies demand that they need to compensate victims who suffered under the nazi regime. David Rosenberg applies, and provides the German bureaucracy with all the documentation he has. The German doctor that studies his case doesnt believe him. David is not able to prove all the claims he is making, according to the German government. This perhaps is not surprising since his psychological vounds are not visible on the outside and since the Germans themselves did all they could to destroy papertrails at the end of the war. The focus of the German government is also to keep economic compensation to as low a number as possible. The refusal of the new German government to recognize what David has gone through eventually pushes him over the edge, and he takes his own life.

The difficulty of receiving compensation and restoring what is lost is also illustrated in the book "The Hare with Amber Eyes" of Edmund De Waal. Like Rosenberg, De Waal tells the story of what previous generations of his own family experienced at the hands to the nazi regime. De Waals family, called the Ephrussis was one of the richest Jewish families in Europe. With wealth that matched the Rothchilds, the main home of the Ephrussi family during the 1930s was what is best described as a small palace along the Ringstrasse in central Vienna. As previous generations had been avid art collectors, the home was filled with artists that today you are likely to find in the Louvre or the Royal gallery. After they nazi takeover in 1938, the Ephrussis had to flee, their home was looted and pretty much all of value was taken away. When the war was over, the family wealth was gone and the Ephrussis did what they could to reclaim what had been stolen from them. Just like for Rosenberg however, they often found that proving what you had lost was often impossible, especially as many people had incentives for not believing you. Anything they did manage to retrieve they sold again to be able to rebuild their lives. The palace was eventually given back to them, but in horrible condition and without the means to restore it this was also sold off at a fraction of the price. The crumbs of the Ephrussi wealth helped get the survivors off their feet, but their heritage as part economic aristrocracy was gone for good.

Some very good answers in this thread! I would also mention this previous question, with top-level answers from u/BigBennP and u/The_Alaskan, plus a bunch of interesting follow-ups by other users: I'm a Jewish man in 1946 recently liberated from a death camp. My home has been destroyed by the war, all my friends and family have been eradicated, I have no money or possessions and all records of me have been destroyed. What do I do and who can I turn to for help?

Something I haven't seen from the other answers but was touched upon by Primo Levi, an Italian Jew who was sent to Auschwitz later in the war, in at least one of his books/interviews (Survival in Auschwitz/If This is a Man, I believe, or it might've been a video interview he did later in his life [perhaps both]) is that for those that were able to sort of re-integrate, there was a fear amongst them that if they didn't write down/speak about what happened right now then by the time that they got older and put some distance from the horrible events and maybe wanted to say something about it, no one would believe them. While this wasn't necessarily the experience of everyone I believe the Primo Levi refers to at least a few others who were with him on his journey back to Italy who agreed with his assessment of things, and that is, ultimately, why Primo Levi decided that he had to write the books that he did and get them published because he didn't want years to pass and him find out that no one believes that what he went through happened.