Yes, you can still use an FSA with a nanny. When you request reimbursement, you might have to enter their SSN (our FSA requires that). Your FSA might have certain rules for reimbursement documentation, so check with them before you get going. You can make a paystub for the checks and then keep a copy of the deposited check. Those are good to have for tax purposes anyway. Any hint of a nanny makes the IRS perk up because so many people pay their nannies illegally, so keeping the paperwork in order is really important. We opted to just pay for a payroll company to manage it, but it can be done individually too.