TurboTax is correct. The maximum that you are permitted to the individual 401(k) is your net profit from self-employment minus the deductible portion of self-employment taxes. With $9,975 of net profit, the deductible portion of self-employment taxes would typically be $705, leaving only $9,270 available to contribute to the individual 401(k). You must obtain a return of the excess contribution or risk the plan being disqualified.
