The format was changed from five series of 16 teams to ten series of 10 teams, as the no relegation rule was applied in the previous season after its suspension due to the COVID-19 pandemic.
Sportul Snagov and Daco-Getica București were dissolved and excluded by the Romanian Football Federation before the start of the new season.
Hușana Huși, CSM Bacău, Pașcani, Axiopolis Cernavodă, Dacia Unirea Brăila, FCSB II, Recolta Gheorghe Doja, Pucioasa, Astra II, Balotești, Sporting Roșiori, Cetate Deva, Filiași, ACS Poli Timișoara, Gilortul Târgu Cărbunești, Unirea Alba Iulia, Industria Galda, Odorheiu Secuiesc and SCM Zalău were spared from relegation due to the interruption of the 2019–20 season, as a result of the COVID-19 pandemic.
The 100 football clubs were placed in 10 series, the first two teams from each series qualified for the promotion play-off, but only the best 5 teams promoted to 2021–22 Liga II season.
The 100 football clubs were placed in 10 series, the last two teams from each series and the worst 8th place qualified for the relegation play-outs, which was played against 21 winners of the 2020–21 Liga IV season.