New single member 401(k) for 2020, Still time?

I know that the Secure Act says that a PS or DB plan can  be adopted for the previous year up to the time the plan sponsor files their taxes.  That December 31 deadline date scramble is no longer for them.  The act did not change the 401(k) rule that says you need to give the NHCEs time to defer for that initial year.  But what if it is a single member plan, a sole proprietor?  Could they adopt a plan now for 2020 and still make deferral contributions in addition to a non elective contribution?  

No. Can't defer on money already earned and their comp was considered earned on 12/31.

If it ever becomes law, section 320 of the Securing a Strong Retirement Act would permit exactly this. However the fact that it is a provision in a new bill is a clear indication that it is not permissible under current law.

https://www.congress.gov/bill/117th-congress/house-bill/2954/text?s=1#toc-H1C6C2AD2785149CFA7E8B441E3DC0C7E

Ok.. my mistake.  I recall reading that single member sole proprietors have until 4/15 of the following year to adopt and fund a 401(k) for the previous year.  No?

Since a sole proprietor's income isn't known until their tax return is completed, they are not required to deposit their deferrals until their income is known. However they are still required to make an election to defer before the end of the plan year.

No as 401k election had to be made by 12/31/2020. No issue with ps or db plan though.

Ok... got it... it's all about the "election" to defer that needs to be by December 31.

Thanks

Well, be a little careful here. IMHO, you cannot make a valid election to defer to a plan that doesn't exist. So merely signing a deferral election in December would not allow you to retroactively adopt a 401(k) the following year and deposit deferrals for that prior year.

Others may have a different opinion on this.

You cannot make a deferral election until the plan is established .  See Treas. Reg. 1.401(k)-1(a)(3)(iii)(A).