Short answer: Voluntary (worksite) benefits are optional coverages employees can buy, usually through payroll deduction. Common ones include dental, vision, accident, critical illness, hospital indemnity, short- and long-term disability, life, and legal or identity-theft plans.
Voluntary or worksite benefits are coverages an employer makes available, often at group rates, that employees choose and typically pay for through payroll deduction. They round out a core medical plan and let employees tailor protection to their needs without much direct cost to the employer.
Common offerings include dental and vision plans; supplemental health products such as accident, critical illness, and hospital indemnity insurance that pay cash benefits to help with out-of-pocket costs; short-term and long-term disability that replace income; group term life and AD&D; and lifestyle protections like legal services and identity-theft coverage. Many of these are excepted benefits, meaning they sit outside core ACA medical rules.
For employers, voluntary benefits can improve recruiting and retention at low cost; for employees, group pricing and payroll convenience are the draw. Review how each benefit coordinates with the medical plan, and note that tax treatment varies (for example, who pays the premium can affect whether disability benefits are taxable).