H-1B temporary workers in specialty occupations and distinguished fashion models: Depends on the validity period of the labor condition application and the proposed period of employment, plus a period of up to ten days before the validity period of the H-1B petition begins and ten days after it ends. Most H-1B workers are initially granted up to a three-year stay. Extensions are allowed up to a maximum total stay of six years (with exceptions, notably for persons who are seeking permanent residence through the job). After getting your H-1B, any time you spend outside the U.S. is added on to and extends your three years.
Generally, a citizen of a foreign country who wishes to enter the United States must first obtain a visa, either a nonimmigrant visa for a temporary stay, or an immigrant visa for permanent residence. Visitor visas are nonimmigrant visas for persons who want to enter the United States temporarily for business (visa category B-1), for tourism (visa category B-2), or for a combination of both purposes (B-1/B-2).
A visa does not guarantee entry into the United States, but allows a foreign citizen coming from abroad to travel to a U.S. port of entry and request permission to enter the United States. The Department of Homeland Security, U.S. Customs and Border Protection (CBP) officials have authority to permit or deny admission to the United States, and determine how long a traveler may stay. At the port of entry, upon granting entry to the United States, the Customs and Border Protection officer will stamp your travel document with the date of admission, the class of admission (i.e. VWP traveler, or the visa classification for visa holders, or other permissible class of entry), and the date that you are allowed to remain until, that is the date by which you must leave the United States. You can review information about admission on the CBP website. The Department of State's Consular Affairs website has more information about duration of stay.
On what basis would she be able to adjust status once in the U.S.? Of course she shouldn't do this. If immigration officials even *think she entered the U.S. on a tourist visa with the intention of immigrating, she'll never adjust status. It's never advisable to enter the U.S. on a tourist visa with the intent of immigrating. http://www.dixonimmigration.com/index.php?pid=2
Some types of visa like B1 may not expire with the expiry of the holder's passport. An unexpired, endorsed visa in an expired passport may be presented for entry into the USA, as long as the visa itself has not been cancelled, is undamaged, is less than 10 years old and is presented with a valid non-expired passport, provided that both passports are for the same nationality.
The Democratic People's Republic of Korea (North Korea) requires that its citizens obtain an exit visa stating the traveller's destination country and time to be spent abroad before leaving the country. Additionally, North Korean authorities also require North Korean citizens obtain a re-entry visa from a North Korean embassy or North Korean mission abroad before being allowed back into North Korea.
All nationals listed in the chart above are eligible to apply online for an e-Tourist Visa (eTV). You must apply at least four days before you arrive in India. You can only enter India via those airports listed on the eTV website. There are five e-Visa subcategories: e-Tourist visa, e-Business visa, e-Medical visa, e-Medical Attendant Visa and e-Conference Visa.