This website provides a brief overview of the topic of U.S. immigration law, an extremely detailed and complex area of law and regulations which by its nature allows only the most cursory treatment here. Specialized legal advice is essential.

Nationals of certain countries may take advantage of the U.S. Visa Waiver Program, which allows visitors to travel to the U.S. for up to 90 days for business or pleasure without a visa.  For details of visa waiver countries, see

U.S. Customs and Border Protection will deny admission to those who would appear to be using the VW program as a means to create residency in the U.S. by leaving and returning frequently, the so-called “revolving door” problem. If a traveler has spent more than 180 days cumulatively in the U.S. in the last 365, he/she is extremely likely to be denied entry on VW program at the next attempt. It is worth remembering that one refusal of entry to the U.S. on VW (delete ‘program’) results in a lifetime ban on ever using the program again. In these circumstances, application must be made to a U.S. embassy abroad for a B-1/2 visitor’s visa. Visa waiver travelers must apply for electronic system travel authorization (ESTA) online in advance of travel – see

Visitors to the U.S. for business or pleasure are not permitted to work.  Visitors for business may engage in certain business activities but not gainful employment – see the section on B-1 visas below for what’s permissible for visa waiver visitors for business.  See our e-Guide for more details here.


People who wish to travel to the United States for reasons of employment are divided into two main categories, immigrant and non-immigrant, or permanent and temporary. Those applying for immigrant visas, commonly referred to as ‘green cards’, wish to remain in the U.S. permanently. The correct term for ‘green card’ is lawful permanent residency. There are many different routes to an employment based ‘green card’, none simple or speedy. Expert representation is essential. Those persons not wishing to remain permanently in the United States may, where eligible, obtain non-immigrant or temporary visas, upon expiration of which they must leave the U.S. unless they have become lawful permanent residents in the meantime.  See our e-Guide for more details here.

The following is a list of the most common temporary visas:

B Visa for Visitors for Business (B-1) or Pleasure (B-2)

The B visa allows a person to enter the US temporarily for business, (B-1), or for pleasure or medical consultation/treatment, (B-2). It is similar to the visa waiver program in terms of eligibility and permissible activities but application at a U.S. embassy and interview are required.  Irish and UK nationals are generally eligible for 10-year multiple entry visas in straightforward cases.   Entry on B visa is usually for 6 months though lengthy periods of time spent in the U.S. without an appropriate work visa will heighten scrutiny by Customs and Border Protection. Clearly permissible business activities for visa waiver/B visitors include attending meetings, conferences and trade shows, engaging in negotiations, litigation, independent research, and taking the necessary steps to facilitate investment in the U.S. leading to an E-2 (investor) visa. Generally, work is not permissible though what constitutes ‘work’ is not always clear as case law in this area is conflicting.  See our e-Guide for more details here.

If you are interested in applying for a B visa, or for more information, please contact us here.

E Visas for Traders (E-1) and Investors (E-2)

Treaty Trader and Treaty Investor visas are available to certain individuals and companies from countries which maintain treaties of friendship and commerce with the U.S., (“Treaty Countries”) including Ireland and UK. Nationals of Treaty Countries or companies which are majority owned by such nationals may be eligible for E-1 Treaty Trader visas if they have sufficient trade with the U.S.; and E-2 Treaty Investor visas where they have invested substantially in setting up business in the U.S.  For a list of countries included, see

The principal trader or investor and executive, managerial and essential skills workers who share the nationality of the treaty trader or investor may be eligible for E visas.   Treaty visas have many advantages; see our e-Guide for more details here.

If you are interested in applying for an E-1 or E-2 visa, please contact us here.

H-1B Professional Visa

The H1-B visa is for professionals – generally bachelor’s (or higher) degree holders and is limited to 65,000 visas worldwide per year, a quota which is woefully short of demand in recent years. The opening date for applications is April 1 each year, for a work start date of October 1, six months later. In recent years, the H-1B quota has been exceeded in the first few days and applications are placed into a random computer generated lottery so it’s a matter of luck whether any particular application is chosen for processing.  Please see our ­Blog for more details here.

If you’re interested in taking your chances on a H1B visa, it’s advisable to prepare well in advance so your petition is ready to file on the first available date – April 1.  You must have a US professional job offer (one which requires a degree) and an employer willing to take the lottery risks and wait until October 1 (all going well) for you to begin working.

Employees of institutions of higher education or a related or affiliated nonprofit entity, as well as those employed, or who will be employed, by a nonprofit research organization or a governmental research organization are exempt from the cap. There is also a quota of 20,000 H-1B visas for foreign workers with a U.S. Master’s or higher level degree. Such persons are statutorily exempted from the annual cap. See our Blog for more details here.

If you are interested in obtaining an H-1B, or for more information, please contact us here.

J-1 Trainee/Internship Visa

The J-1 visa is a temporary training (for up to 18 months) or internship visa (12 months) for foreign nationals who wish train in their chosen career or profession in the U.S. for a maximum of 18 months (12 months in the catering industry, unless managerial).  The purpose of this visa is to foster understanding and share business models between the U.S. and other countries so an underlying requirement is that candidates intend to return to their home country at the end of the training/internship period. Contrary to popular perception, one may train at any time during one’s career, so this visa is not limited to newly qualified or young people. A college degree is not necessary and there is no annual quota for this visa category.  See our e-Guide for more details here.

Irish graduates may avail of a 12-month Intern J-1 Work and Travel visa to allow them to work and travel in the US for a maximum of 12 months, after which an H-1B or other category of work visa will be required for those who wish to remain working in the US.


For more information on applying for a J-1 visa, please contact us here.

L-1 Intra-Company Transfer Visa

The L-1 intra-company transfer visa allows executives and managers, (L-1A), and employees with specialized knowledge, (L-1B), to transfer from a foreign company to a U.S. branch, subsidiary or affiliated company. The applicant must have been employed by the non-U.S. company as an executive, manager, or specialized skill worker for a minimum of twelve months during the three years immediately preceding the filing of the L-1 visa petition.

L-1 visas are generally best suited to companies whose US operations are already established. For more information see our e-Guide here.

If you are interested in applying for an L-1 visa, please contact us here.

O-1 Visas for persons of extraordinary ability in Business, Science, Athletics or the Arts, Motion Picture/TV

The O-1 category is for highly talented or acclaimed foreign nationals who have risen to the very top of their field and who can demonstrate extraordinary ability or achievement. O’Brien & Associates is proud to have represented many successful business people and talented artists in obtaining O-1 visas to work in the U.S.

For more information on applying for an O visa, please contact us here.


Family Based

Family based lawful permanent residence (‘green card’) is available to immediate relatives of U.S. citizens, including spouses, unmarried children under 21, parents of U.S. citizens over 21, and spouses of deceased U.S. citizens in certain circumstances. It is also available to preference immigrants, in order of preference, 1st, unmarried children of U.S. citizens over 21 years, 2nd , spouses or children of ‘green card’ holders, 3rd, married children of U.S. citizens, and 4th, siblings of U.S. citizens over 21 years. The process is reasonably fast for immediate relatives but takes many years for preference immigrants.

For more information on applying for a family-based green card please contact us here.

Employment Based

There are 5 categories of employment based ‘green card’:

  • First Preference, Priority Workers, (EB-1), includes Persons of Extraordinary Ability, Outstanding Professors and Researchers, and Multinational Executives and Managers
  • Second Preference, (EB-2), Advanced Degree or Exceptional Ability Aliens
  • Third Preference, (EB-3), Skilled Workers, Professionals and Other Workers
  • Fourth Preference, (EB-4), Special Immigrants, including Religious Workers, Returning Immigrants and others
  • Fifth Preference, (EB-5), Investment and job creation

Unless labor certification (known as PERM) can be bypassed by filing a first preference petition, there are 3 stages to obtaining a ‘green card’:

  • Labor Certification, now called PERM
  • Immigrant Visa Petition; and
  • Adjustment of Status (if physically in the U.S.) or Consular Processing (if abroad)

Obtaining an employment based ‘green card’ is a complex, lengthy and expensive process but unavoidable for those wishing to work and live in the U.S. permanently. Expert legal representation is essential.

For more information on applying for an employment-based ‘green card’ please contact us here.

We look forward to being of assistance.