max ER contribution?

Is there a maximum percent of eligible pay that the NFP has to stay below?  In the for-profit world, they have to stay below 25% to keep the contribution deductible... but there's no deduction issue for a non-profit.  Whether or not a NFP should be spending 30% of payroll on a plan contribution is another question altogether, but if they had the cash, is there anything stopping it?  I'm sure there is, but I haven't found it yet.  Thanks.

I don't think so. Years ago, back when the PS deduction limit was 15%, I did RK for the large/audited PS 401k of a very generous NFP that easily exceeded that threshold every year without issue. Total compensation and benefits still need to be reasonable but there's no hard coded limit of which I'm aware.

Agreed, a tax exempt employer or government employer is not subject to the excise tax [IRC Section 4972(d)(1)(B)].  Because of this a tax exempt employer could exceed the IRC Section 404(a)(3) deductible limit for Profit Sharing Plans without having the excise tax imposed.  However, the applicable dollar limits under IRC Section 415(c) must not be exceeded.