Is a Deferred Compensation retirement payment elgible for a Solo 401K contribution?

[TaxFart]

I received a deferred compensation payment 1 month after I retired from my employer of 30 years.  This will appear as W2 income, likely in box 11 - nonqualified plans. Since I am no longer employed at the company I am not eligible for contributions to their 401k plan.  Can I make a contribution to a solo 401K plan using this income? 

[VolvoGirl]

Why W2?  I think it will be on a 1099R form.   

[TaxFart]

W2 is the way the company has decided it should be paid. And on a W2 form there is box 11 - nonqualified plan income.

[dmertz]

Nothing on a W-2 from this employer will support a solo 401(k) contribution.