I formed a single-member LLC in 2021. But, did not receive any income in 2021. Do I need to report the formation in order to write off start-up cost and formation costs?

Yes, in order to claim the start up costs, you would need to enter the new business on your tax return.  Depending on how you filed your LLC if you are considered a disregarded entity you will just enter it on Schedule C

As you walk through the questions in TurboTax Home and Business or TurboTax Self-Employed, you will be asked if you started or stopped this business in 2021.  Answer yes and you will be guided through entering your start up costs. 

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