Closeout is the wind-down that formally hands a finished building to the owner: completing the punch list, passing final inspections, and assembling the closeout package — as-builts, warranties, O&M manuals, attic stock, lien waivers, and the certificate of occupancy.
It's the phase that most affects whether you get paid the last dollar and the retainage — and the phase teams most often let drag. A disciplined closeout releases the money, protects the warranty relationship, and leaves the owner with everything they need to operate the building.