This is not true. A pass-through entity simply means that the LLC does not pay taxes. It does however keep separate records and submits separate tax forms than you do personally.

It goes like this:

  LLC files form 1065
    Form 1065 includes income / expenses of the LLC
    Attached to form 1065 is a form K1 for each member
      Form K1 includes the (net profit/loss * member's % ownership) + guaranteed payments (like a salary)

  You file form 1040
    Attached to form 1040 is your copy of the K1, which gets treated as additional income
    You may also attach your personal business expenses [1]
    You pay taxes on this ammount

Your LLC then mails in the 1065 + K1s. Then you send in your 1040 + K1s + the taxes you owe personally.

So you see, LLCs file tax forms completely separately, it's only the check you have to write to the government that's "pass-through".

[1] Your personal business expenses are expenses that came out of your personal account for a business expense, so like a reimbursable expense. This gets reported on your personal taxes rather than the company's separate business expenses that came out of the company account. In general, just try not to do this if you can help it, as it just makes things more confusing.