COI terms, from the GC’s side

A subcontract asks for insurance in one dense sentence, usually some version of:

“…named additional insured on a primary and non-contributory basis, with a waiver of subrogation and 30 days notice of cancellation.”

Here’s what each piece means when you’re the one requiring it — and, more usefully, what to actually collect to prove it. The thing they all share: the certificate of insurance is not the proof.

Every term in that sentence, decoded

• …with a waiver of subrogation…Waiver of subrogationYour sub's insurer giving up its right to come after you for money it paid on a claim — so the loss stops there.
• …shall name Contractor as an additional insured under Subcontractor's commercial general liability policy…Additional insuredAdditional insured status puts you on your sub's liability policy, so their insurer defends and pays claims caused by their work — not yours.
• …on a primary and non-contributory basis…Primary and non-contributoryPrimary and non-contributory means the subcontractor's policy pays first and in full for a covered claim, without demanding your policy chip in.
• …and 30 days notice of cancellation.30 days notice of cancellationA requirement that you're warned before the sub's policy is canceled — so a lapse doesn't surprise you mid-job. In practice the certificate rarely delivers it, so track the expiry yourself.
• Subcontractor shall furnish a Certificate of Insurance (ACORD Form 25) evidencing the coverages required herein prior to commencement of Work.ACORD 25 (Certificate of Liability Insurance)Read it in six zones: the issuing agency, the named insured, the lettered carriers, the coverage grid, the description box, and the holder box.
• Prior to commencing work, Subcontractor shall furnish a certificate of insurance evidencing the coverages and limits required under this Agreement.Certificate of insurance (COI)A certificate tells you that on the day your sub's agent typed it, a policy with those numbers appeared to exist. Nothing further.
• Subcontractor shall name Contractor as an additional insured and shall furnish a certificate of insurance listing Contractor as certificate holder prior to commencement of work.Certificate holder vs. additional insuredCertificate holder just means you got a copy — it grants no coverage. Additional insured means you're added to the sub's policy and actually protected.
• …and shall maintain Workers' Compensation insurance for the duration of the Work…Workers' comp exemptionSome owner-only subs are genuinely exempt — but that shifts injury and audit risk onto you, so collect the state exemption certificate and require real coverage the moment they bring a crew.
• …the general aggregate limit shall apply separately to this Project…Per-project aggregateA sub's general aggregate is shared across every job they work — so a claim elsewhere can run it out before yours. The CG 25 03 endorsement gives your project its own dedicated limit.
• …as additional insured for ongoing and completed operations…CG 20 10 vs CG 20 37CG 20 10 covers you as additional insured while the sub is working; CG 20 37 covers you after the job is done. You need both — completed-operations is where defect claims surface years later.
• …Commercial General Liability written on an occurrence basis…Occurrence vs claims-madeAn occurrence policy covers a claim by when the work happened; claims-made covers it by when the claim is filed — so a claims-made sub can lose coverage for your job the moment they switch carriers.
• …Workers' Compensation and Employers Liability with limits of not less than [$X]…Employers liabilityEmployers liability is the half of workers' comp that covers lawsuits over a workplace injury — including the case where a sub's injured worker sues you and you turn to the sub's policy.
• …Umbrella or Excess Liability in excess of the primary coverages…Umbrella vs excess liabilityBoth stack extra limit on top of the sub's GL, auto, and employers liability. An umbrella can also be broader and drop down to fill gaps; excess just follows the underlying form and adds limit.
• …Automobile Liability covering any auto, including hired and non-owned vehicles…Automobile liabilityThe sub's vehicle coverage. The limit is rarely the problem — the covered-auto boxes are, because they decide whether a hired truck is covered at all.
• …including products and completed operations coverage, maintained for [N] years following final completion…Products & completed operationsThe part of the sub's general liability that answers after their work is finished. It carries its own aggregate, separate from the general one.
• …the Subcontractor shall be the named insured under each policy required herein…Named insuredThe company the policy actually belongs to. If it is not the exact legal entity you signed the subcontract with, the certificate covers someone else.
• …placed with insurers rated not less than A- VII by A.M. Best…AM Best ratingA carrier's financial-strength grade. The letter is the strength, the Roman numeral is the size, and the certificate does not print either.
• …Subcontractor shall maintain an Experience Modification Rate (EMR) of not greater than 1.00…Experience modification rateA number comparing a subcontractor's actual workers' comp claims to what is expected for their trade and size. 1.00 is average. Below is better.
• …Subcontractor shall furnish loss runs for the three most recent policy years upon request…Loss runsThe insurer's own claim history for a policy — every claim reported, what has been paid, and what is still reserved against it.
• …Subcontractor shall enroll in the Owner Controlled Insurance Program (OCIP) for the Project…Wrap-up insurance (OCIP / CCIP)One policy bought centrally for a whole project, covering everyone enrolled. Owner-controlled is an OCIP; contractor-controlled is a CCIP.