How do I enter business expenses if I am part owner of LLC and am reporting income using a K-1 (1065) form?

The rules for deducting your expenses related to your Schedule K-1 Form will depend on exactly what type of income your K-1 Schedule is reporting. 

In any case, you will need to upgrade to TurboTax Home & Business in order to deduct any business, rental property or royalty, estate/trust, or investment property expenses that exceed $100.

In most cases, all expense deductions are taken directly on the Partnership Return (Form 1065) prior to issuing individual partners K-1's. In this case, you would not be able to take the deductions again on your personal tax return.

In other cases, however, if there are expenses that you did not report on your partnership return, these expenses may be entered in the area of TurboTax that relates directly to the type of income your K-1 reflects. For instance, if there is income from rental property or royalty income, you may be able to deduct your related expenses on Schedule E along with your individual tax return. 

Instructions for partners for reporting information on their individual return from Schedule K-1(Form 1065), can be found here:  https://www.irs.gov/instructions/i1065sk1/ch02.html#d0e721

Using TurboTax Deluxe or higher, navigate to the following areas to enter your Schedule K-1 Form information:

Federal Taxes ('Personal' using Home & Business)< Wages & Income ('Personal Income' using Home & Business)< "I'll Choose What I work On" or scroll down through All Income< Business Investment and Estate Trust Income (as pictured in screenshot below)

Answer all the questions about your K-1 and then TurboTax will guide you to the appropriate area to enter any expenses not already accounted for on the partnership  return that are associated with the income reported on your K-1.