It depends. If the LLC is a single-member entity and is the same business you reported under the DBA, you may simply change the business name for Schedule C from the Business Profile (under the Business tab). In this situation, the IRS considers you and the business to be one entity, so Schedule C covers the entire year (regardless of the business name).

If, however, you have elected for the LLC to be taxed as an S-Corp, you will need to file a separate return for this entity (Form 1120-S, available in TurboTax Business).