It’s no secret that applying for residence in the United States can be a complicated process. Even when all the paperwork is in, there’s still a long wait involved, a wait that is determined by a complicated equation that balances the demand and supply of employment and family-unification visas the U.S. grants. As a result, some applicants have been waiting in line for more than 10 years, others for more than 20 years, according to the State Department’s most recent count.

"The question is how long do you expect people wait to reunite family members, individuals with their spouses?" asks Madeleine Sumption, a policy analyst with the Migration Policy Institute.

According to Sumption, the long waiting lines for green cards is one more problem that congressional inaction on immigration reform has caused. Lawmakers have two choices to address the long waiting line: either increase the number of visas available or reduce the number of people eligible.

While, there are no limits on visas for immediate relatives (spouses, minor children and parents) of U.S. citizens, there are long waits for other family members, including spouses and young children of legal permanent residents; unmarried adult sons and daughters of citizens; and siblings of citizens. In some cases, people have died waiting to be given a visa number.

Meanwhile, on the employment-based visa front, Sumption says that a vast majority of the people on the waiting list are already in the U.S. on temporary work visas. That means those workers are vulnerable to exploitation by their employers–they are tied to their employers, have little leverage to seek new opportunities, and have no room to engage in the entrepreneurship our economy values, said Sumption.

Here’s a breakdown of the current wait times for family-sponsored visas and employment-based visas.