From TurboTax Deluxe online edition, you cannot add a S-corporation tax return. To file a business tax return including a S-corporation, you would need to purchase TurboTax Business to complete your filing.
TurboTax Business is a
separate TurboTax product line for customers to file S Corp, C Corp,
partnerships, estates, trusts and multi-member LLC. It is not part of the
TurboTax personal taxes editions ( Free edition/ Basic, Deluxe, Premier and
Home & Business)
Please see attached link for information.
https://turbotax.intuit.com/small-business-taxes/
