Small businesses that file Schedule Cs on Form 1040, Partnerships filing Form 1065, Sub-S Corporations Form 1120S and LLCs that have pass-through income may claim the  20% deduction against income. Limitations apply to high earners in certain service fields. Phase out begins at $315,000 for Joint Filers and $157,000 for Single, Married Filing Separate and Head of Household.

SEPs, SIMPLE IRAs, payroll deduction IRAs, profit sharing plans, 401k arrangements and defined benefit plans are options for Small Business retirement. IRS Publication 3998 is a helpful brochure that compares payin limits, eligibility, the employer's role, withdrawal and borrowings, vesting, filing requirements and other basic operational rules for the various plans.