For which category of income can a partner not take a loss greater than their interest basis?

A partner cannot take a loss greater than their interest basis when dealing with ordinary income. This is a critical aspect of partnership tax treatment, as the tax code limits the ability of partners to deduct losses to the extent of their basis in the partnership.

The basis represents the partner's investment in the partnership, and losses that exceed this basis cannot be utilized for ordinary income or any other type of income. This restriction is in place to prevent partners from deducting losses that exceed their actual investment in the partnership, which maintains the integrity of financial reporting and tax obligations.

In contrast, other income categories like capital gains, passive income, and portfolio income have different rules associated with them regarding losses and deductions. However, the limitation regarding deducting losses that exceed basis is strictly enforced for ordinary income, ensuring that partners cannot claim losses that exceed what they have invested in the partnership.