WDO Inspection
A wood destroying organism inspection covers fungi and wood-decay organisms as well as insects. A termite inspection does not. The distinction is written into state law, and it decides which document you actually need.
WDO and WDI are different scopes
They read like interchangeable jargon. They are not.
WDO (wood destroying organism) includes fungi and wood-decay organisms. Florida statute defines it as arthropod or plant life, naming termites, powder-post beetles, oldhouse borers and wood-decaying fungi. Washington's code defines it as insects or fungi that consume or excavate wood.
WDI (wood destroying insect) is insects only. The form used for federally-backed mortgages, the NPMA-33, is titled the Wood Destroying Insect Inspection Form. To report fungi at all, an inspector has to attach a separate optional document.
The two names sit side by side in California's own paperwork. The state's required report is Form 43M-41, the Wood Destroying Pests and Organisms Inspection Report. The federal mortgage form is the Wood Destroying Insect Inspection Form. One covers fungi; the other does not. California Structural Pest Control Board advisory.
The NPMA-33 is an industry form, not a federal one
It is written and copyrighted by the National Pest Management Association, a trade body, and adopted by HUD and the VA, not issued by them. HUD's own form field reads "Form NPMA-33 or State mandated infestation report", which is the whole point: where a state prescribes its own document, the state's document governs. NPMA's own completion guidance says the same, and states plainly that the NPMA-33 does not preempt state requirements.
California is a worked example. Its board has stated that state law does not recognise the NPMA-33 in lieu of Form 43M-41, though nothing stops a company issuing the NPMA-33 in addition to the required state form.
Who orders one
Usually a lender or a party to a property sale, rather than the homeowner. Requirements vary by loan programme and by state, and some of the guidance circulating online cites documents that have since been superseded, so treat any specific claim about a loan programme as something to confirm with the lender directly.
Who can sign one
That varies by state, and it is the part most people miss. In California the report must be issued by a registered company and the inspection carried out by a licensed Branch 3 Field Representative or Operator. Every business listed here holds a current licence with a termite and WDO category in its state's register.