Partner — co-development with a vendor on a structured non-standard engagement — is structurally under-chosen in enterprise agentic AI procurement in 2026. Procurement committees have templates for build and buy but none for partner, so the third path does not get evaluated on an equal footing. The vendor-lock-in and change-management dimensions of the GAUGE framework usually favour partner when it is honestly evaluated, not buy or build.

Claim scoped to enterprise agentic AI procurement specifically. 60-day review cadence. Watches: (1) aggregate analyses showing partner outcomes statistically indistinguishable from buy, (2) major consultancies adopting three-path templates (Gartner, Forrester, McKinsey), (3) regulatory procurement frameworks structuring partner-style engagements as a distinct third path.