For Disaster Loss, this is the IRS article: https://www.irs.gov/taxtopics/tc515

For a qualified disaster distribution and the three-year reporting option, this was proposed in June 2021: H.R.3954

https://www.congress.gov/bill/117th-congress/house-bill/3954/text?r=1&s=1

(4) INCIDENT PERIOD.—The term “incident period” means, with respect to any qualified disaster, the period specified by the Federal Emergency Management Agency as the period during which such disaster occurred (except that for purposes of this Act such period shall not be treated as beginning before December 28, 2020, or ending after the date which is 30 days after the date of the enactment of this Act).

...

(5) INCOME INCLUSION SPREAD OVER 3-YEAR PERIOD.—

(A) IN GENERAL.—In the case of any qualified disaster distribution, unless the taxpayer elects not to have this paragraph apply for any taxable year, any amount required to be included in gross income for such taxable year shall be so included ratably over the 3-taxable-year period beginning with such taxable year.

So, watch that bill; if it passes it will have retro-active effect to your taxpayer.