Purpose: Pictures consistently referred to by the same name (high agreement) are named faster than pictures that elicit inconsistent responses across individuals (low agreement). Although this effect is more pronounced in older adults apparently due to slower lexical selection, it is unclear whether this is consistent for different types of low agreement pictures. We investigated whether pictures with different sources of disagreement have differing selection requirements, as indexed by naming latencies. Method: Picture naming latencies were compared for 20 young (ages 18-35 years) and 20 older adults (ages 60-80 years) across 3 object naming conditions--high name agreement, low name agreement due to multiple correct names, and low agreement due to abbreviations and elaborations. Results: Compared to high agreement items, responses were slower specifically for low agreement items with multiple names, and to a lesser extent, items with abbreviations and elaborations (p < 0.001). Older adults were slower than younger adults, especially for low agreement items with abbreviations and elaborations (p = 0.031). Conclusions: Our findings indicate differential lexical selection requirements for low agreement pictures, depending on the reason for agreement being low. This demonstrates the importance of differentiating the source of disagreement in any experimental or clinical assessment of picture naming.