On 16 March 2020, FERJ suspended the Campeonato Carioca indefinitely due to the coronavirus pandemic in Brazil.
[4] Originally, the relegated team Nova Iguaçu obtained an injunction from the Tribunal de Justiça Desportiva do Futebol do Estado do Rio de Janeiro (TJD/RJ) that guaranteed their presence in the 2021 Campeonato Carioca First Round,[5] but the Superior Tribunal de Justiça Desportiva (STJD) overturned the decision and Nova Iguaçu were relegated to 2020 Série B1.
[7] The top two teams of the preliminary phase qualify for the main competition while the remaining four compete in the relegation round.
The four lowest placed teams in the preliminary round form Group X and play a double round-robin.
Like the Taça Guanabara, the top two teams in each group standing qualify to a semi-final with the same format.
[7] The final stage only is contested between two teams, as opposed to the four-team bracket of previous seasons.
Additionally, the best-placed team in the combined table that is not one of the "Big Four" of Rio de Janeiro (Botafogo, Flamengo, Fluminense, Vasco da Gama) wins the Taça Independência (Independence Cup) and also qualifies to the 2021 Copa do Brasil.
Originally, the four teams — excluding the "Big Four" and Taça Independência winners — with best overall performance (only considering matches against non-Big Four teams) would compete in the Torneio Extra (Extra Tournament): a single-elimination semi-finals and final bracket, with the winner receiving a berth to the 2021 Copa do Brasil.
Home team was decided in a draw held on 14 February 2020, 14:00 at FERJ headquarters in Rio de Janeiro.
Home team was decided in a draw held on 6 July 2020, 10:00 at FERJ headquarters in Rio de Janeiro.
[6] As best-placed team in the overall table, excluding the "Big Four", Volta Redonda won the Taça Independência and qualified for the 2021 Copa do Brasil.
[11] The Relegation Round was competed from 18 January to 4 July in two separate double round-robin groups.
They, originally, obtained an injunction from TJD/RJ that guaranteed their presence in the 2021 Campeonato Carioca First Round,[5] but STJD overturned the decision and Nova Iguaçu were relegated to 2020 Série B1.