US Senate
- February 15, 2020 – March 22, 2020: Democratic ward and town committees around the state hold caucuses elect delegates to send to the Massachusetts Democratic Party convention.
- May 30, 2020: The Massachusetts Democratic Party holds its annual convention in Lowell, at which each candidate must receive at least 15% of delegates present to make the primary ballot. (Note: this was cancelled due ot the pandemic.)
- September 1, 2020: Primary for Congressional, legislative, and county elections