Is a cash bonus for referring a new employee taxed the same way as regular wages?

Yes. A cash referral bonus paid for successfully referring a new employee is taxable income to whoever receives it, the same way as wages, and it's subject to the usual withholding that applies to other employment payments. This holds whether or not the recipient is themselves an employee of the company paying it out — the payment itself triggers the tax treatment, not the exact relationship between payer and recipient.

If you're an existing employee who refers someone and gets paid a bonus for it through your employer, that amount is simply added to your employment income, generally through the same payroll process as your regular pay. If the referral bonus is paid to someone who isn't otherwise an employee of that company, it's still taxable income to that person, though the specific mechanics of how it gets reported and any withholding applied can differ depending on the exact arrangement and relationship involved.

Either way, don't treat a referral bonus as a casual, tax-free thank-you payment just because it's framed informally or feels more like a reward than a wage. If you receive one, expect it to show up as reportable income, and keep track of it for your own tax filing regardless of how your employer characterizes the payment.