In most states, sole proprietors with no employees are not legally required to carry workers' compensation insurance. Workers' comp laws are generally written to protect employees, and if you have no one working for you, there's usually no one the law requires you to cover. However, this is not true everywhere, and the exceptions matter.
A handful of states and industries change this general rule. Construction and certain high-risk trades (roofing, excavation, electrical work) often require workers' comp coverage even for owner-operators with zero employees, because the injury risk is considered too high to leave uninsured. Some states also mandate coverage once you bring on even one part-time or casual worker, so the moment you hire help, the rules can shift immediately. A few states require sole proprietors in specific fields to carry coverage regardless of employee count, so checking your state's labor or industrial commission website is the only reliable way to know for sure.
Even where it isn't legally required, many sole proprietors choose to buy a policy anyway, and there are practical reasons for that. If you get injured on the job, your personal health insurance may not cover lost income, and workers' comp can replace a portion of your wages while you recover. General liability insurance, which many business owners already carry, does not cover your own injuries, only damage or injury you cause to others or their property. If you work in a physically demanding trade like landscaping, contracting, or delivery driving, a single injury without income replacement can be financially devastating.
There's also a contractual angle that catches a lot of solo operators off guard. General contractors, property management companies, and larger businesses frequently require anyone they hire, including independent one-person operations, to show proof of workers' comp coverage before they'll sign a contract. In states that allow sole proprietors to opt out, you can sometimes get an official exemption certificate to prove you're not required to carry it, which satisfies these clients without making you buy a policy you don't need.
If you do want coverage as a sole proprietor, look into what's sometimes called an "owner-operator" or "sole proprietor" workers' comp policy. These policies let you elect coverage voluntarily and set your own assumed payroll amount, which determines both your premium and your benefit level if you're ever injured. Rates vary significantly by state and industry classification, so it's worth getting quotes from a couple of insurers or an independent agent who handles small business coverage.
The bottom line: check your specific state's requirements, since rules vary more on this topic than almost any other small business insurance question. If you're in a higher-risk trade, work with general contractors, or simply can't afford to go without income if injured, voluntary coverage is worth serious consideration even when it isn't mandated by law.