"In the client's case, he did not inform me of making that election in the prior year, so 1/3 of the income did not appear on the 2021."

Just keep in mind that is Opposite of how it works. It will be spread over three years unless the client elects not to do so and instead will report it all in that first year.

Q6. When do I have to pay taxes on coronavirus-related distributions?

A6. The distributions generally are included in income ratably over a three-year period, starting with the year in which you receive your distribution. For example, if you receive a $9,000 coronavirus-related distribution in 2020, you would report $3,000 in income on your federal income tax return for each of 2020, 2021, and 2022. However, you have the option of including the entire distribution in your income for the year of the distribution.