** LEGAL UPDATE **
Polish nationals can, as of November 11, 2019, enter the U.S. and spend up to 90 days in the country without first obtaining a visa. That's because Poland has officially begun participation in the U.S. Visa Waiver Program (VWP). Inclusion on this list is reserved for countries with high U.S. visa approval rates and whose governments agree to share information on criminals and suspected terrorists with the U.S. government.
The main benefit to travelers using the VWP is ease of U.S. entry. Prospective business or pleasure travelers who meet the basic requirements (in particular, who have never violated the terms of any past nonimmigrant visa, are not inadmissible, do not intend to stay in the U.S. longer than three months (90 days) much less permanently, and will not be arriving on a private aircraft or other non-VWP approved air or sea carrier), can arrange for U.S. entry with minimal bureaucratic requirements or documentation.
The main steps to getting VWP entry are to obtain a passport with a data chip containing biometric information and apply for and receive authorization through the U.S. State Department’s Electronic System for Travel Authorization (ESTA).
Of course, travelers will still be screened upon U.S. entry. And they should understand the limitations of the VWP before deciding to skip getting an actual visa; for example, the inability to extend or change one's status in the United States. See Nolo's articles on Visiting the U.S. for Business, Pleasure, or Medical Treatment for details on the various possibilities.
Effective Date: November 11, 2019