B-1 in Lieu of H-1B
There are many high tech companies that need to get short term work done in the U.S. that would be generally considered work and normally an H-1B visa would be appropriate for that. However, due to the short duration and the frequency of such work, under some limited circumstances, you may get an employment-authorized B1 visa to do H-1B type work.

This is useful in case
  • A U.S. company would like to bring in an employee of an overseas subsidiary, affiliate, or parent company for a short duration.

  • A foreign company needs to send an employee to the U.S. for a limited period to conduct a specific project for the U.S. company.

Eligibility
As long as all of the following criteria are met, you can get a B-1 visa to do H-1B work in the U.S.:
  • You must have the equivalent of a U.S. bachelor's degree.

  • You plan to perm H-1B caliber work or training. In other words, your work must be in a "specialty occupation".

  • You can complete the task in a short duration.

  • You will not receive any salary or compensation from a U.S. source. You can still get the reimbursement of incidental travel expenses such as housing and per diem.

  • You are a permanent employee (not a contractor) of the foreign employer and you will be paid only by your foreign employer.

Requirements
  • At the time of visa interview, carry a letter from your foreign employer and the U.S. company that will specify the work to be performed, duration of the stay and the remuneration plans.

    If your employer participates in the Business Executive Program (BEP), these details can be mentioned in the BEP cover letter as well.

  • You may expect more scrutiny than a normal business visa application.

  • You should carry the same letters at the port of entry and be prepared to explain your travel purpose and your source of pay.

  • All other normal requirements of getting a B-1 visa apply in this case as well, such as eligibility, strong ties to the home country etc.

  • If you receive a multiple entry B-1 visa in such case, you can use it later even for regular B-1 visa related activities. If you receive a multiple entry B-1/B-2 visa, you can use it later even for tourism purposes, as long as there are no special annotations on the visa stamp.

    However, if you have not received 'B-1 in lieu of H-1B' by explicitly specifying, be careful not to do any work which may be considered employment. It is illegal to work on a B-1 visa. If you are caught, your visa will be cancelled and you will be deported. Additionally, you will also face major difficulties in getting another visa in the future.