As of March 2016: Many student founders who are just graduating start with applying for Optional Practical Training (OPT). Those in STEM fields are eligible to pursue the one time STEM OPT extension. See this other FAQ article for more information on OPT and STEM OPT Extension or visit the MIT International Student Office's employment page for details.
Once student founders are on OPT they often simultaneously begin the process of applying for a work visa. Visa rules change frequently and we strongly recommend that you work with an attorney who specializes in immigration issues to understand your options. Visit the US Department of State's web page on employment visas for details. Many of our previous student founders have looked into either the H1-B or the O categories of temporary work visas. However, as mentioned, the rules change frequently so do consult legal counsel who specializes in immigration law for advice.
For student founders who have an extraordinary ability or are outstanding professors or researchers, they may be eligible for an employment-based, first preference visa called the EB-1. The bar is high for this path. Consult an immigration lawyer to see if this is an option that might be open to you.
Note that Trust Center is not equipped to provide legal or immigration advice. Please visit the ISO and talk to your advisor, or engage legal counsel who specializes in immigration issues to understand the latest rules and to interpret how these rules and policies apply to your personal situation.