If you are a self-insured employer (regardless of your size), you are required to report the names and Social Security numbers for all individuals enrolled in your employer’s group health plan. This includes employees, dependents, and any other non-employees covered by your plan.
The IRS requires self-ensured employers to make a “reasonable effort” to obtain Social Security numbers for all individuals covered under their insurance plan. If, after making a reasonable effort, you are unable to obtain a dependent’s SSN, you can instead provide a date of birth for that covered individual.
For your protection, we recommend that you document all attempts to obtain a dependents Social Security number, as the IRS may require proof of reasonable effort.