It is claims-made, and that changes everything

General liability responds to when the damage happened. Professional liability responds to when the claim is made. Let it lapse and the work you did last year is bare, however long you carried the policy while doing it. The retroactive date is the single most important item on the certificate.

Design-build is the obvious trigger, delegated design is the quiet one

A contractor who never calls themselves design-build still takes on design risk the moment they engineer a connection, size a system or submit a deferred approval. That is delegated design, and it is a professional exposure.

Rectification cover is what makes it useful

Some contractors’ professional forms pay to correct a design error found before it causes third-party damage. Without it, the policy only responds once someone else has sued, which is usually the more expensive outcome.

Contractor Professional Liability

Professional liability is the line contractors are least often sold and most often need without knowing it. General liability responds to bodily injury and property damage. It does not respond to a design that was wrong, a specification that was misread, or a means-and-methods decision that turned out badly and injured nobody but cost the owner money. As soon as a contractor’s scope includes deciding rather than only building, that exposure exists.

Professional liability in each state

The same line, governed five different ways. Each state page publishes the sources behind these figures.

California

Contractors State License Board (CSLB)

CSLB does not require professional liability for any classification. Demand is contractual, and it arrives with design-build delivery — which California public agencies use widely — and with any deferred-approval or delegated-design scope.

All California requirements →

Oregon

Construction Contractors Board (CCB)

No CCB endorsement requires professional liability. The CCB sets general liability limits by endorsement and stops there, so a design-build Oregon contractor can be fully compliant with the board and carry nothing at all for the design half of their scope.

All Oregon requirements →

Washington

Department of Labor & Industries (L&I)

L&I registration requires a bond and general liability only. As with Oregon, a registered Washington contractor doing design-build meets every state requirement while the design exposure sits entirely uninsured unless a contract forces the issue.

All Washington requirements →

Louisiana

State Licensing Board for Contractors (LSLBC)

The LSLBC requires general liability and workers’ compensation for residential and home-improvement licenses, and no professional liability for any license type. Design-build exposure here is governed purely by the contract.

All Louisiana requirements →

Arizona

Registrar of Contractors (ROC)

The ROC requires neither general nor professional liability. Arizona is therefore the state where a contractor is most likely to be carrying no cover at all for a design decision, because nothing in the licensing process ever raises the question.

All Arizona requirements →

What actually moves the price

How much of your scope is design-build or delegated design
Whether you employ or subcontract the design, and whether the design sub carries their own cover
Contract language accepting responsibility for means and methods, or for the sufficiency of a design
Project size and the size of the economic loss a mistake could cause — this line insures money, not injury
Claims-made mechanics: retroactive date and tail, because the policy in force when the claim is MADE is what responds

Contractor professional liability