Box 19A shows your MLP cash distributions. Here's exactly how they affect your adjusted basis, step by step.
Box 19A on your Schedule K-1 reports cash distributions received from the partnership during the tax year. For most MLP investors, this is the quarterly distribution you see deposited in your brokerage account. Unlike dividends reported on a 1099-DIV, these distributions are a return of capital that reduces your partner basis under IRC §733.
The IRS Partner’s Basis Worksheet processes distributions on Line 13. First, your basis is increased by income allocations and liability changes. Then distributions reduce it. If distributions exceed your pre-distribution basis, the excess is taxable as capital gain under §731. The worksheet ensures losses are limited before distributions are applied.
19A is cash distributions (most common). 19B is marketable securities distributed in kind (rare for publicly traded MLPs). 19C is other property distributions. For typical MLP investors, only 19A will have a value.
Important: Box 19A is not the same as taxable income. Your taxable income from the MLP comes from Box 1 and other income boxes. Distributions and taxable income are two separate concepts that both affect your basis but through different lines of the worksheet.