Self-employed individuals and businesses employing only the owner, partners and spouses have several options for tax-advantaged savings: a Solo 401(k) plan, a SEP IRA, a SIMPLE IRA, or a Profit Sharing plan. Each option has distinct features and amounts that can be contributed to the plan each year. Use the Solo 401(k) Contribution Comparison to estimate the potential contribution that can be made to a Solo 401(k) plan, compared to Profit Sharing, SIMPLE, or SEP plan.