Blanket vs. Scheduled Additional Insured Endorsements for HVAC Companies

A blanket additional insured endorsement automatically adds any party your written contract requires to your general liability (GL) policy. Nobody gets named on the form. A scheduled endorsement does the reverse and lists each additional insured by hand. For an established HVAC company signing dozens of general contractor (GC) agreements a year, that difference decides how much certificate paperwork your office runs.

What is a blanket additional insured endorsement?

A blanket additional insured endorsement is GL wording that automatically grants additional insured (AI) status to anyone your signed contract obligates you to add. Nobody gets listed on the form. A scheduled endorsement works the opposite way, naming each AI, and often the address, before coverage attaches to that party.

AI status hands your customer defense and payment under your policy for claims that grow out of your work. A GC who requires it wants your insurer, not theirs, absorbing a suit tied to your crew's install. (That's also why GCs pair the AI demand with a primary and noncontributory request, so your policy pays first.)

The blanket-versus-scheduled call trades convenience against control. Blanket wording clears a certificate of insurance (COI) request the same day, because the contract itself triggers coverage. Scheduled wording forces a fresh endorsement request, a carrier turnaround, and sometimes a fee for every new party you add.

CG 20 10 vs CG 20 38: the ISO forms behind each

The scheduled-versus-blanket choice comes down to which Insurance Services Office (ISO) form your carrier attaches. CG 20 10 is the scheduled form. CG 20 33 and CG 20 38 are the blanket forms. The common "CG 20 10 vs CG 20 38" question is really scheduled-and-named against blanket-and-automatic for ongoing work.

Editions matter as much as the numbers. Current forms like CG 20 10 04 13 cover the named insured's ongoing operations and require your work to be a cause of the loss, per IRMI. The old CG 20 10 11 85 was broader and sometimes reached completed operations, but carriers rarely issue it now.

CG 20 38 is the one worth asking for on subcontracted jobs. It extends AI status to upstream parties, such as the owner sitting above your GC, even without a direct contract between you and that owner. CG 20 33 stops at parties you sign with directly.

Should an HVAC company carry blanket or scheduled coverage?

An established HVAC company should default to a blanket additional insured endorsement and keep scheduled endorsements in reserve for clients who demand a named form. Once you add five or more parties a year, blanket wording pays for itself in saved admin time and same-day certificates. Large corporate and government clients sometimes still require their name scheduled, so hold that option open.

Run the math on a mid-size service book. Say you sign 40 contracts a year that each require AI status. At $50 per scheduled endorsement, that's $2,000 in fees plus a carrier wait on every COI.

A blanket form priced at a flat $150 clears all 40 the day each contract is signed. That efficiency is why blanket wording sits inside the broader HVAC company insurance program most established shops run.

One mechanical contractor client of ours ran everything scheduled and lost a Friday bid, because the certificate could not be endorsed before the deadline. Switching to a CG 20 38 blanket form ended the scramble, and the next bid's certificate went out within the hour. Larger jobs layer on more umbrella and excess bid requirements beyond additional insured status.

Does a blanket endorsement cover completed operations?

A blanket additional insured endorsement does not cover completed operations. Forms CG 20 33 and CG 20 38 both stop at ongoing operations. Those are the claims that arise while your crew is still on the job. Damage that surfaces after the job is finished falls under completed operations, and neither blanket form reaches it.

Picture a rooftop unit your crew installed in the spring. A refrigerant line fails eighteen months later and floods the tenant suite below. That is a completed-operations claim, and the GC's blanket AI status on your policy does nothing for it.

Covering the GC there takes CG 20 37, the scheduled completed-operations form the Insurance Journal flags for that gap. Some carriers restrict completed-operations AI coverage, so it can be harder to obtain.

A broker reads the bid spec and matches the stack to it. CG 20 33 or CG 20 38 handles ongoing work, and CG 20 37 gets added when the contract reaches into completed operations. Coverwatch builds that endorsement stack against the actual contract language before a certificate goes out.

What does an additional insured endorsement cost?

Additional insured endorsement cost depends on the type. Carriers usually charge $25 to $75 for each scheduled endorsement. A major general contractor or owner on a large project can run $300 or more. Blanket coverage is typically a flat $50 to $200 a year, and many contractor carriers fold it into the base premium.

Some carriers price blanket wording as a load on your GL premium instead of a flat fee, usually in the low single digits as a percentage. For a shop signing dozens of contracts, the blanket route almost always costs less than paying per certificate. It also drops the turnaround delay that scheduled forms build in.

One HVAC client of ours budgeted $60 per scheduled endorsement and ran about 30 a year. That is roughly $1,800 in fees, before anyone counted the staff hours chasing carrier confirmations. A blanket form at $175 flat cut the line item and cleared the office manager's endorsement queue.

Match the endorsement to the contract, and the certificate stops being a fire drill. Coverwatch reviews GC bid specs and builds the additional insured stack for HVAC clients as part of its flat-fee HVAC contractor insurance practice.