Last updated: October 2026 — Pricing verified: October 2026 — Next review: Q2 2027. Pricing changes often; verify before committing.
This guide is educational; consult your insurance agent or broker before binding coverage. It is not legal or insurance advice.
Methodology: This guide is built from the standard ISO form library, current carrier pricing ranges collected from independent agents in October 2026, and public regulatory guidance on commercial general liability endorsements. Prices reflect typical U.S. ranges and vary by carrier, state, and gross receipts.
The short answer: Most commercial general liability (CGL) policies can add a per-project aggregate with one endorsement: ISO form CG 25 03. The per-project aggregate (CG 25 03 04 13) resets your full general aggregate limit separately for each job, so one bad claim on Project A does not drain the limit the GC is relying on for Project B. Call your agent, ask for the CG 25 03 endorsement, confirm it is on the policy, and make sure the certificate of insurance lists it. This is a national endorsement form with identical mechanics in all 50 states, and it typically costs an additional $250 to $1,500 per year depending on your gross receipts.
TL;DR
- The GC wants a dedicated project aggregate because your single general aggregate is shared across every job you run that year. One form fixes it: CG 25 03 04 13.
- Adding the per-project aggregate CG 25 03 endorsement usually costs $250–$1,500/year; the endorsement itself is standard ISO language, not a custom rewrite.
- A certificate of insurance (COI) does not grant coverage — only the endorsement attached to the policy does. Ask for the endorsement PDF, not just a box checked on the ACORD 25.
- If your carrier writes on non-standard forms or your policy already shows a per-location aggregate, confirm the wording actually matches what the subcontract exhibit demands before you sign.
What is a per-project aggregate endorsement?
A per-project aggregate endorsement is an add-on to your general liability policy that gives each construction project its own separate general aggregate limit. The standard ISO version is form CG 25 03 04 13 ("Designated Construction Project(s) General Aggregate Limit").
Without it, your policy has one general aggregate for the whole policy year. If you carry a $1M-per-occurrence / $2M-aggregate policy and a claim on one job eats $1.5M of that aggregate, every other GC you work for that year is suddenly sharing a nearly-empty limit. That is exactly the exposure the GC's risk manager is trying to close.
With CG 25 03 attached, each designated project gets its own full aggregate. A claim on Project A does not reduce the limit protecting Project B.
Why the GC is asking
The insurance-requirements exhibit in your subcontract almost always says something like "General Aggregate to apply per project" or "Contractor shall maintain a dedicated per-project aggregate." When a GC wants a dedicated project aggregate, they are protecting the limit they underwrote their own job against. It is a reasonable ask, and in commercial subcontracting it is close to standard.
Can my policy do that? The 4-step workflow
Here is the exact sequence to run from the moment the exhibit lands to the moment the COI clears the GC's compliance portal. Carry one real input through it: a subcontract exhibit demanding "$2,000,000 General Aggregate, applied per project."
Step 1 — Read the exhibit language precisely. Note whether it says "per project" or "per location." They are different endorsements (CG 25 03 vs. CG 25 04). Copy the exact phrasing so your agent matches it word for word.
Step 2 — Call your agent and request CG 25 03 by name. Ask: "Can you add the Designated Construction Project(s) General Aggregate Limit endorsement, form CG 25 03 04 13, and what is the additional premium?" A clear, formatted request gets a faster, more accurate quote.
Step 3 — Get the endorsement issued and request the PDF. Do not accept a verbal yes. Ask for the actual endorsement document showing your policy number, the form edition date, and the designated-projects schedule. Confirm the premium in writing.
Step 4 — Verify the COI reflects it, then submit. The ACORD 25 should reference the per-project aggregate in the Description of Operations box. Remember: the certificate is only evidence — the endorsement attached to the policy is what grants the coverage. Submit both to the GC's portal.
What it costs
For most trade subcontractors, the added premium runs $250 to $1,500 per year. The number scales with your gross receipts, class code, and loss history. A small specialty sub may land near the bottom of that range; a high-receipt mechanical or structural contractor may sit at the top. Because the endorsement multiplies the aggregate limit the carrier is exposing, pricing is tied to revenue rather than a flat fee. Verify the current quote before binding — rates move.
Common pitfalls
- Per-location is not per-project. If your policy already carries CG 25 04 (per-location aggregate), it does not satisfy a per-project requirement. Confirm the form number.
- Non-standard carrier forms. Some surplus-lines and non-admitted carriers use proprietary language. Read the proprietary wording against the exhibit demand; equivalent intent is not enough if the GC's compliance software is matching form numbers.
- Relying on the COI alone. A checked box on the certificate proves nothing if the endorsement was never attached. Always obtain the endorsement PDF.
Frequently asked questions
Is CG 25 03 the same in every state? Yes. It is a national ISO form with identical mechanics in all 50 states, though premium varies by state, carrier, and your receipts.
Does adding it increase my per-occurrence limit? No. It separates the general aggregate per designated project. Your per-occurrence limit is unchanged.
How fast can my agent add it? Often within a few business days, assuming the carrier allows the endorsement mid-term. Ask about any mid-term premium adjustment.
Sources and further reading
- Insurance Services Office (ISO), commercial lines form directory — verisk.com/insurance/products/iso-forms (accessed October 2026).
- National Association of Insurance Commissioners (NAIC), consumer guidance on commercial liability coverage and policy endorsements — content.naic.org (accessed October 2026).
- Associated General Contractors of America (AGC), construction risk and insurance resources — agc.org (accessed October 2026).