A legislative creation
The MEI was not created by a single individual. Brazil established the Microempreendedor Individual category through Complementary Law No. 128, dated December 19, 2008. The law was approved by the National Congress and signed by the president of the Republic.
The legislation amended Complementary Law No. 123/2006, known as the General Law for Micro and Small Businesses, adding a simplified route to formalization for people working on their own account. So the most precise answer is that the MEI was a legislative creation of the Brazilian state, rather than the personal initiative of one politician or agency.
When the system took effect
The MEI was created in law in 2008, but the rules governing the category began to take effect on July 1, 2009. The distinction matters: the date the law was enacted is not the same as the date the new system began operating.
The change addressed the situation of people who worked independently but remained informal. The MEI was designed as a simpler way to formalize small businesses, obtain a CNPJ business registration number, pay taxes, and contribute to Brazil’s social security system. Formalization can also provide access to social security rights and certain benefits associated with operating as a legal entity.
What the answer means
In short, Congress approved Complementary Law No. 128/2008, which established the MEI in law, and presidential approval confirmed the legislation. Its rules took effect the following year. This sequence is why the answer is not the name of one person: the category came about through federal legislation and public policy.
The MEI is a Brazilian legal category intended to formalize people who work for themselves as small business owners. Its creation does not mean that every independent worker automatically qualifies. There are specific requirements, including carrying out an eligible activity and complying with the rules for the category. The law explains where the MEI came from; eligibility is a separate question.