A Self-Directed Solo 401(k) allows self-employed individuals and small business owners to invest in real estate using their retirement funds. Unlike traditional retirement accounts, this plan offers higher contribution limits, tax-deferred or tax-free growth (Roth option), and checkbook control, enabling direct real estate purchases without custodian approval. Investors can buy rental properties, commercial real estate, land, and more while benefiting from tax advantages. However, IRS rules, such as the prohibited transactions rule, must be followed to avoid penalties. A Self-Directed Solo 401(k) for real estate is a powerful tool for long-term wealth building.