Should I report the noncash contributions sold by my organization's hired third parties in Schedule M?

If your organization hired or used a third party or any related organizations to solicit, process, or sell any noncash contributions received, then it is necessary to report them in Schedule M by answering "Yes" to line 32a, Part I, Types of Property and must describe these arrangements in Part II, Supplemental Information.
 
However, if the third party mentioned is a broker who sells publicly traded securities that are gifts received by the organization, then there's no need to mention them. You can answer as "No" in line 32a, Part I of Schedule M.

If your organization is required to report schedules other than A, B, and G, we recommend choosing our interview-based filing method.