Yes, the IRS uses 3 years. Therefore, if you have not worked for the employer for over 20 years, you should be able to say that the work was not treated as wages for a former employer and that it qualifies for as qualified business income.
See the IRS reference from Publication 535 below -- note the bold print:
Services performed as an employee excluded from qualified trades or businesses.
The trade or business of performing services as
an employee is not a trade or business for purposes of section 199A. Therefore, any amounts
reported in box 1 of Form W-2, other than
amounts reported in box 1 where the “Statutory
Employee” box in box 13 is checked, are not
QBI. If you were previously an employee of a
business and continue to provide substantially
the same services to that business after you are
no longer treated as an employee, there is a
presumption that you are providing services as
an employee for purposes of section 199A for
the 3-year period after ceasing to be an employee. You may have to rebut this presumption
upon notice from the IRS by providing records
such as contracts or partnership agreements
that corroborate your status as a non-employee. For more information on whether you
are an employee or an independent contractor,
see Pub. 15-A, Employer’s Supplemental Tax
Guide, and Pub. 1779, Independent Contractor
or Employee.
