Washington-based think-tank has calculated that over four lakh Indians in US may have to wait at least 151 years for the highly coveted green card.

The green card authorises foreigners to live and work in the US permanently.

The projections come after the US Citizenship and Immigration Services (USCIS) recently released number of applicants for such cards.

The calculation by the Cato Institute is based on the number of green card issuances in 2017.

As of April 20, 2018, there were 632,219 Indian immigrants and their spouses and minor children waiting for green cards, also known as legal permanent residency cards.

For green card, the shortest wait is for the highest skilled category for EB-1 immigrants with “extraordinary ability”. EB stands for employment based.

According to the Cato Institute calculations, the  extraordinary immigrants from India will have to wait “only” six years.

According to the USCIS, there are 34,824 Indian applicants under EB-1 category. Along with their 48,754 spouse and children, 83,578 Indians are in line for green card under EB-1 category.

EB-3 immigrants— those with bachelor’s degrees— will have to wait about 17 years, Cato Institute said. As of April 20, there were 54,892 Indians in this category. Clubbed with 60,381 spouses and children, the total number of Indians waiting for green card in EB-3 category are 1,15,273.

However, the biggest backlog is for EB-2 workers, who have advanced degrees.

“At current rates of visa issuances, they will have to wait 151 years for a green card. Obviously, unless the law changes, they will have died or left by that point,” Cato institute said.

According to the USCIS, there were 2,16,684 primary Indian applicants under EB-2 category and 2,16,684 spouses and children, thus making a total of 4,33,368.

In 2017 only 22,602 Indians were issued the legal permanent residency cards. Of these 13,082 were in the EB-1 category, 2,879 in EB-2 category and 6,641 in Eb-3 category, according to the latest USCIS figures.