An immigration attorney explains that immigration law is as complex, or maybe more so, than tax law and it features lots of gray areas. For example, there are numerous visas which allow people to come into the U.S. and each one has a different name and different rules. Some allow a person to work while they are in the U.S., others don't. Some are for multiple years while others are for shorter periods of time. Also, with names like the H-1B and J-1, talking about visas can turn into "alphabet soup," she says.