Here is the IRS bulletin regarding deadline extensions for certain things:   https://www.irs.gov/pub/irs-drop/n-20-35.pdf   ... View more

Based on my own experience, if your 2019 over-contribution (due to employer ADP testing failure) was refunded to you before April 15, 2020, then you will receive a 2020 1099-R in January 2021.  You would include the 1099-R in your 2020 return (if code 8 is used in box 7) and it will be added to your income and taxed as regular wages.  TurboTax added my 1099-R to my regular W2 wages.   This is how I do it, as my employer's plan fails ADP testing every year and I will receive a 1099-R every year.   There is guidance out there that says you should include the over-deferral amount in your 2019 wages.  You may opt to do that, however, you will definitely receive a 1099-R for the year in which actual distribution occurs.  Then you will have to explain to the IRS that you already reported the 1099-R in the previous year. ... View more

@romeshdaisy Yes, I have the same situation that you mentioned.  My employer failed ADP testing and had to return excess 401(k) deferrals to about 6 employees.  This is for 2018 deferrals.  Checks were issued by Fidelity and returned to employees prior to April 15, 2019.  Employees received a 2019 1099-R, with a distribution code 8 in box 7 which has the definition of (Excess contributions plus earnings/excess deferrals (and/or earnings) taxable in 2019.  So under these circumstances, we would not add the excess deferrals to our 2018 income because they are taxable in 2019 -- the year of distribution. ... View more