Both the individual 401(k) and SEP contribution entries are in the same self-employed retirement section of TurboTax under Business Deductions and Credits (under Wages & Income). Answer Yes to an individual or Roth 401(k), make sure all boxes on the next page are blank, then answer Yes to a Keogh, SEP or SIMPLE contribution, enter your employer contribution as a SEP contribution, then confirm that the self-employed retirement deduction on Schedule 1 is the same as what you entered as a SEP contribution.
