"We have received the Presidential assent to the Food Security bill," Food Minister K V Thomas told PTI.
The law will soon be notified in the Government gazette, after which it will come into effect, he added.
The Centre has convened a meeting of state food ministers and secretaries to discuss the rules and regulations for implementing the scheme, which is being touted as a game changer by the ruling government.
The two-day meeting is scheduled from October 3, Thomas said.
The food security law, which has been described by the ruling Congress as a "game changer" and slammed by the Opposition as a "gimmick" before the 2014 Lok Sabha elections, guarantees 5 kg of rice, wheat and coarse cereals per month per person at Rs 3, Rs 2 and Re 1 respectively.
India will now join the select league of nations that guarantee foodgrain to a majority of their population.
At Rs 1,30,000 crore government support, the food security programme will be the largest in the world. It will require 62 million tonne of foodgrains.
