Publication 560 (2021), Retirement Plans for Small Business 1 Net earnings from self-employment must take the contribution into account. See Deduction Limit for Self-Employed Individuals in chapters 2 and 4. 2 Compensation is generally limited to $290,000 in 2021. 3 Under a SIMPLE 401(k) plan, compensation is generally limited to $290,000 in 2021.