Section M is the part of a federal solicitation that defines the evaluation criteria — the factors, subfactors, and weights the government will use to score proposals. It tells the offeror exactly what the source selection authority cares about, in what relative importance, and how the integrated assessment will be conducted. Section M is the answer key to the source selection. Every word of the proposal should be written to Section M's stated factors.
Section M typically lists evaluation factors in descending order of importance (or with explicit weights), defines what acceptable, marginal, and unacceptable mean for each factor, and specifies the relationship between non-price and price factors. Common evaluation factor structures include adjectival ratings (Outstanding/Good/Acceptable/Marginal/Unacceptable), color ratings (Blue/Green/Yellow/Red), or numerical scoring. Subfactors add detail under each top-level factor. The relative weighting language — "significantly more important than," "approximately equal," "less important than" — drives the tradeoff math during best-value source selection.
For small contractors, the proposal-writing strategy must be built directly from Section M. Every page of the technical volume should map back to a Section M factor or subfactor. Firms that win small-business competitions consistently outline their proposal against the Section M structure first, then write to it. Firms that lose typically write generic proposals that fail to address the specific factors the government has called out. Section L instructions tell you how to write; Section M tells you what to write.