Dear Halina,
Travel is exciting, but you are wise to ask these questions before you go. The short answer is that you should not lose your benefits. They should stay in place while you are out of the country, and you should not need to reapply once you come home. That said, there are some important things to be aware of, which I will explain below.
First, you should inform the agencies that handle your benefits that you will be out of the country temporarily. Be sure to tell them that you are going on vacation, not moving to another country. Make it clear that your absence will be temporary.
Social Security
Your benefits will continue while you are gone. But one question to ask yourself is this: will you need your checks sent to you in Germany or Poland? The federal government will send checks to some countries, but not others. To my knowledge, this should not be a problem for Germany or Poland. There may be staff at the American embassies there who can help make sure you get your checks. Of course, that is most helpful if you are staying in or near the cities where the embassies are. (Note that even if you stay abroad longer than you expect to, you can continue to get your checks as long as you are still eligible.) Of course, you can also continue to have SSA direct deposit your checks into your US bank account. That is what I would advise, because it is simpler and probably a bit safer.
Medicare (Federal program)
Medicare stays in place while even while a person is out of the country. However, with a few rare exceptions, the program will not pay for any healthcare or medical costs that you incur while you are out of the country. The exceptions only apply to very specific situations related to travel in or near Canada or Mexico, or on a ship. As you can see, the exceptions will not apply to your stay in Germany and Poland.
Medical Assistance (MA)
Medical Assistance (MA) is the Minnesota health insurance program. As with Medicare, benefits remain in place while you are gone, as long as your absence is only temporary. And of course, this program will also not cover you in Europe. If you receive MA, you must tell the county in advance about any planned absence from Minnesota. You should tell the county the date you plan to leave, the date of your return, and the reason you will be gone. After your absence, you must return to Minnesota.
MA is a need-based program, so if you have MA, you should be careful about what you pay for during your vacation. You should not pay travel, hotel, meal, or other costs for any other people. Pay only for your own travel expenses and keep your receipts. If you pay for other people’s expenses, the county will consider that to be gifts, and such gifts are likely to cause you to lose your eligibility.
It is wise to have health and medical coverage during your stay abroad. (You may even want to check to see if the countries you are visiting require it, since you will be staying for a while.) If you have a supplemental health insurance policy, you should check to see if it includes coverage in foreign countries. If it does not, you may want to purchase a policy that does.
The bottom line: inform the agencies before you go, investigate a foreign health insurance policy to cover you while you are abroad, and be careful how you spend your money. And one more thing - have a wonderful time!