Validity period Adjusted visa refusal rate The Adjusted Refusal Rate is based on the refusal rate of B visa applications. B visas are adjudicated based on applicant interviews; the interviews generally last between 60 and 90 seconds. Due to time constraints, adjudicators profile applicants. Certain demographics, such as young adults who are single and unemployed, almost never receive visas, unless they articulate a compelling reason. Adjudicators are evaluated on how fast they carry out interviews, not the quality of adjudication decisions. The validity of B visa decisions is not evaluated. To qualify for the Visa Waiver Program, a country must have had a nonimmigrant visa refusal rate of less than 3% for the previous year or an average of no more than 2% over the past two fiscal years with neither year going above 2.5%. In addition, the country must provide visa-free access to United States citizens and has to be either an independent country or a dependency of a VWP country (which has precluded Hong Kong and Macau from participating in the program). (Until April 4, 2016, Argentina charged $160 to U.S. citizens to enter.) The Adjusted Visa Refusal Rates for B visas were as follows: Overstay rate A number of visitors overstay the maximum period of allowed stay on their B-1/B-2 status after entered the U.S. on their B-1/B-2 visas. The Department of Homeland Security publishes annual reports that list the number of violations by passengers who arrive via air and sea. The table below excludes statistics on persons who left the United States later than their allowed stay or legalized their status and shows only suspected overstays who remained in the country. The top 20 nationalities by the number of suspected in-country B-1/B-2 overstays in 2016 and 2017 were: The top 10 nationalities by in-country B-1/B-2 visa overstay rate are: Use for other countries US tourist visas that are valid for further travel are accepted as substitute visas for national visas in the following territories: – 90 days – 30 days; USD 100 visa waiver fee applies – 90 days; 71 countries — 30 days; USD 50 visa waiver fee applies. — 30 days — up to 6 months; only citizens of may apply the Electronic Travel Authorization (eTA) for visa-free visit or transit (arriving by air). — 90 days; for nationals of China only. — 90 days; for nationals of China, India, Thailand, and Vietnam. —