What Is a WDO Inspection? The Termite Report Explained

Awaiting expert review. This page covers safety or regulatory rules that change over time. It is kept out of search results until a qualified reviewer has checked it; the sources below are dated so you can verify each point.

Quick answer

A wood-destroying organism (WDO) inspection is a visual check of a building’s reachable areas by a licensed inspector for termites, wood-boring beetles, carpenter ants, carpenter bees and, in some states, wood-decay fungi, written up on a standard report.

It is most often ordered during a home sale or refinance. Most states use the national NPMA-33 form; some, such as California and Georgia, require their own. The report is not a warranty or a structural damage report.

Quick facts

The key facts about Wood-Destroying Organism (WDO) Inspection, with sources:

Common form: NPMA-33 Wood Destroying Insect Inspection Report ¹
Pests covered (NPMA-33): Termites, carpenter ants, carpenter bees, reinfesting wood-boring beetles ¹
Not covered (NPMA-33): Mold, mildew and non-insect wood-destroying organisms ¹
Valid for a loan or sale: Within 90 days of the inspection; not a 90-day warranty ¹
Scope: Visual, readily accessible areas; probing and sounding of wood ¹
State forms: Where a state mandates its own form, HUD says that form must be used ²³
California form: Form No. 43M-41 under 16 CCR §1996 ⁴

Key takeaways

A WDO inspection is a visual check for termites and other pests that eat or tunnel in wood, usually tied to a home sale.
Most states use the NPMA-33 report, but a state that mandates its own form overrides it.
The report covers only what the inspector could see and reach that day; hidden damage may exist.
It is not a warranty and not a structural damage report, and it is valid for a sale or loan for 90 days.
A “box B” finding of visible evidence calls for a closer look at damage by a structural professional.

What a WDO inspection is, in plain words

A WDO inspection is a licensed inspector’s search for pests that eat or nest in wood. Termites are the best known, but carpenter ants, carpenter bees and some beetles also damage wood. The inspector walks through the building looking for signs of these pests and the damage they leave.

Lenders, buyers and sellers order it because termite damage is often hidden. The EPA notes that termites are rarely seen outside their tunnels, so many owners learn about them only when they swarm or when damage turns up during work on the house ⁵.

The terms overlap. “WDI” means wood-destroying insect. “WDO” means wood-destroying organism, a wider term that can include wood-decay fungi.

The national NPMA-33 form is a WDI report: it covers termites, carpenter ants, carpenter bees and reinfesting wood-boring beetles, and leaves out mold, mildew and non-insect organisms ¹. California’s state report has a separate “Fungus/Dryrot” finding ⁴.

People also call the result a “termite inspection report” or a “termite letter.” Our termite inspection service page covers inspections done outside a sale.

Not a warranty, not a damage report

The NPMA-33 says the report reflects conditions on the inspection date and is not a guarantee against hidden or future infestation. It also says it is not a structural damage report ¹.

How the inspection is done

These steps follow the NPMA-33 form and NPMA’s published guidelines for completing it.

Scope set. The person ordering the inspection says which structures to cover, such as “house and detached garage” ².
Visual inspection. The inspector checks readily accessible areas, including attics and crawl spaces that allow entry ¹.
Probing and sounding. Unobstructed wood is probed or tapped to find hollow or damaged spots ¹.
Evidence logged. Live insects; dead insects, wings, frass (droppings), shelter tubes, exit holes or staining; and visible damage are each recorded with locations ¹.
Obstructions listed. Areas blocked by stored items, insulation, wall coverings and so on are noted. Crawl spaces with less than 24 inches of clearance under the joists may be called inaccessible ¹.
Recommendation made. The inspector says whether treatment or other action is recommended ¹.
Report signed. The inspector signs with a state license or certification number; the seller and buyer sign too ².

Nothing is torn open. The form says no inspection was made in areas that would need breaking into, dismantling or moving things such as moldings, floor coverings, insulation, furniture or appliances ¹.

Forms and report types you may see

Form or type	Where used	Key points
NPMA-33 (WDI report)	Most states; FHA and VA loans	National form; approved for FHA and VA loans; insects only ¹
State-mandated form	States with their own required form	HUD Mortgagee Letter 95-33: the state form must be used there ³
Official Georgia Wood Infestation Inspection Report	Georgia	The only form permitted for property transfers in Georgia ³
California WDO report (Form 43M-41)	California	Findings include subterranean termites, drywood termites, fungus/dryrot, other findings and further inspection ⁴
Complete, limited, supplemental or reinspection report	California report types	Marked on the form ⁴
NPMA WDO attachment	Where a state or area requires WDO reporting	NPMA model attachment for reporting fungus with the NPMA-33 ²

Example: reading an NPMA-33 with “box B” checked

This is an invented report used to show how the form’s sections fit together. The section names and the guideline rules in the right column come from the NPMA-33 and NPMA’s completion guidelines.

Section	What this example report says	What the rule is
II.A / II.B findings	Box B checked	B is checked for ANY visible evidence, regardless of age or extent ²
II.B.2 evidence	Shelter tubes on the crawl space pier; no live termites	Dead insects, frass, shelter tubes, exit holes or staining go here ¹
II.B.3 damage	Damaged sill plate near the pier	Inspector does not judge structural vs cosmetic damage ²
III recommendation	Treatment recommended for subterranean termites	For subterranean termites: evidence plus no documented prior treatment means treatment should be recommended ¹
IV obstructions	Crawl space: insulation and stored items	Inaccessible areas are listed; hidden damage may exist ¹
V comments	No treatment records provided	Prior treatment documents and service agreements go here ²

What should the buyer do next? The form says that if box B is checked, some damage, including hidden damage, may be present, and a qualified structural professional should assess it ¹. A pest company quotes the treatment; a structural pro judges the repair.

The termite inspection report: where you will see it

The report is the paper output of a WDO inspection. It turns up at several points in a sale.

In the loan file. The NPMA-33 states it is approved for FHA and VA loans ¹. Whether a lender requires one depends on the loan program, the area and what the appraiser sees.
In the purchase contract. Many contracts make the sale depend on a clear report or on agreed treatment and repair.
At closing. The buyer signs to confirm getting both pages; the seller signs to confirm disclosing known history of infestation, damage, repair and treatment ¹. NPMA says these signatures are usually collected by the agent or closing firm ².
In a termite warranty file. Service agreement details, including expiration date, belong in Section V ². See termite warranties and bonds.

Layers The five sections of the NPMA-33

I. General informationCompany, license number, inspector, date, structures
II. Inspection findingsA: no visible evidence, or B: live insects, evidence, damage
III. RecommendationsTreatment or action, or why none
IV. Obstructions and inaccessible areasBasement, crawl space, attic and a coded key
V. Comments and attachmentsPrior treatment, warranties, photos

Page 2 explains scope and limits and is part of the report. Read both pages. Source: [1] [2]

What a WDO inspection gives a buyer or owner

A trained second look at signs that most people miss, such as shelter tubes and frass ¹.
A standard form that lenders and agents know how to read ¹.
A record of what was blocked from view, so you know what was not checked ¹.
A recommendation tied to written guidelines, not to a sales pitch ².
A list of conditions that invite wood-destroying insects, from the form’s consumer advisory ¹.

What the inspection does not tell you

Hidden areas. The NPMA-33 says infestation or damage may exist in concealed or inaccessible areas, and the firm cannot guarantee it found all of it ¹.

Damage extent. NPMA’s guidelines say the inspector is not a damage expert; damage noted is just evidence of current or past infestation ².

Fungus and decay. The NPMA-33 does not cover mold, mildew or non-insect organisms ¹. In states that require WDO reporting, a separate attachment or state form covers fungus ²⁴.

The future. The report reflects one day. It is not a warranty unless one is attached or required by state rules ¹.

Ask to make blocked areas visible

If Section IV lists a blocked crawl space or a cluttered garage, the form says the company can be called back to inspect once the area is made accessible. An extra fee may apply ¹.

What drives the cost of a WDO inspection

We do not list prices. The cost of a WDO inspection depends on the size of the home, the number of structures included, crawl space or basement access, and whether your state requires its own form and filing.

Re-inspections after treatment or after blocked areas are opened may cost extra; the NPMA-33 notes an additional fee may apply ¹.

The larger cost is what a positive report triggers. Treatment is quoted separately, and damage repair is a structural question. Our termite treatment cost estimator shows what drives treatment prices, and the pest control cost guide covers the rest.

On timing, the NPMA-33 is invalid for securing a mortgage or settling a sale if not used within 90 days of the inspection ¹. A delayed closing can mean paying for a new one.

From ordering to closing: the usual sequence

Order it early. Ask the lender or agent which form your state and loan need.
Use a licensed company. The form asks for the company’s state license number and the inspector’s certification, registration or license number ². Check it on our pest control licensing page.
Clear access. Move stored items from crawl space entries, attic hatches and garage walls.
Read both pages. Page 2 explains scope and limits and is part of the report ¹.
If box B is checked, get a treatment proposal from a licensed company and a damage assessment from a structural professional ¹.
Gather records. Prior treatment documents can change the recommendation ².
Close within 90 days of the inspection date, or plan for a new report ¹.

Owner upkeep that keeps the next report clean

The NPMA-33’s consumer advisory lists conditions that invite wood-destroying insects. Fixing them is ordinary home maintenance ¹.

Earth-to-wood contact and foam insulation at the foundation touching soil.
Faulty grade and poor drainage.
Firewood, wood debris or wood mulch against the structure.
Poor ventilation and moisture, including in the crawl space. See our page on crawl space encapsulation for pest prevention.
Tree branches touching the building, landscape timbers and wood decay.

The EPA adds: keep soil around the foundation dry, fix leaks promptly and do not store firewood against the house ⁵.

Warning signs and when to act

Signs worth reporting to an inspector include mud shelter tubes on foundations or piers, winged insects swarming indoors, discarded wings, small piles of frass, exit holes in wood, and wood that sounds hollow when tapped.

The EPA suggests probing exposed wood with a flathead screwdriver to find hollow spots ⁵. Our page on subterranean termites shows what mud tubes look like.

Act quickly when live insects are found. NPMA guidelines say that if live termites are seen, treatment or corrective action should be recommended whether or not the home was treated before ².

Use a licensed company for treatment. The EPA advises choosing a company licensed by your state and asking when it is safe to re-enter after treatment ⁵. See our termite control service page.

Do not open walls or treat on your own

Leave probing behind finishes, crawl space entry and any treatment to licensed pros. Termite products used wrong can contaminate a home and nearby drinking water wells, the EPA warns ⁵.

Rules that govern WDO reports

HUD and VA (federal loans). The NPMA-33 states it is approved for FHA and VA loans ¹. NPMA’s guidelines say it must be used for WDI inspections in HUD/VA transactions unless a state requires its own form ².

Georgia’s commission cites HUD Mortgagee Letter 95-33: where a state mandates a form, that form must be used ³. When an inspection is required depends on the loan program and area; ask your lender for the current rule.

NPMA-33 edition. NPMA’s current completion guidelines are version 1.3, dated August 2019 ². Each printed form carries its own revision date and an “obsolete after” date in the footer ¹; check that yours is current.

Georgia. Under the Georgia Structural Pest Control Act rules, only the Official Georgia Wood Infestation Inspection Report may be issued for a transfer of real property (Notice 15-01, February 10, 2015) ³.

California. Title 16, California Code of Regulations §1996 requires reports under Business and Professions Code §8516(b) on Form No. 43M-41 (Rev. 10/01, required from July 1, 2003), delivered to the person who requested the inspection even if it was free ⁴.

Pesticides. Any treatment that follows uses EPA-registered termiticides under FIFRA, applied by a state-licensed company ⁵.

WDO inspection vs other inspections

Inspection	What it looks for	Who does it	Output
WDO / WDI inspection	Wood-destroying insects (and fungi where required)	Licensed pest inspector ²	NPMA-33 or state form ¹⁴
General home inspection	Overall condition of the house	Home inspector	Home inspection report
Routine termite inspection	Termite activity, often under a warranty	Pest control company	Service ticket or warranty record
Structural assessment	Extent of damage and repairs	Qualified structural professional ¹	Engineering or repair report

Decision guide What to do after the report comes back

If Box A: no visible evidence: Then File it; close within 90 days ¹
If Box B with live insects: Then Treatment should be recommended ²; get a licensed quote
If Box B, evidence only, no treatment records: Then Treatment should be recommended ¹; look for old records
If Box B with visible damage: Then Have a structural professional assess it ¹
If Areas listed as inaccessible: Then Open them up and ask for a re-inspection ¹

Source: [1] [2]

A home inspector may note signs of termites, but the WDO report is the document lenders accept for wood-destroying insects.

Common WDO report myths

Myth A clean report means the house has no termites.: Reality It means no visible evidence in accessible areas that day; hidden infestation may exist ¹.
Myth The report is good for 90 days like a warranty.: Reality The 90 days is a validity window for a sale or loan. The form says it is not a 90-day warranty ¹.
Myth The inspector will tell me how bad the damage is.: Reality NPMA says the inspector is not a damage expert and should not judge structural vs cosmetic damage ².
Myth Every state uses the NPMA-33.: Reality States with a mandated form, such as Georgia and California, require their own ³⁴.
Myth Old damage with no live bugs needs nothing.: Reality For subterranean termites, the form says treatment should still be recommended when evidence is found and no prior treatment is documented ¹.

How your state changes the report

The form you get depends on your state. Georgia allows only its Official Georgia Wood Infestation Inspection Report for property transfers ³. California requires Form 43M-41, which adds fungus and dryrot findings ⁴.

Elsewhere the NPMA-33 is the usual form, and NPMA says state inspection rules take priority over its own guidance ². Termite pressure also differs by region, which affects how often lenders and buyers ask for a report. Our termite risk tool shows the risk level for your area.

When a WDO inspection matters to you

If you are buying, order one even when the lender does not require it, especially in an area with high termite risk. Ask for the form your state requires, and read page 2.

If you are selling, gather any treatment records and warranty papers first. NPMA says documented treatment can change the recommendation ².

If the report finds evidence, separate the two questions: who treats it, and who judges the damage. Our guide to choosing a pest control company helps with the first.

Quick decision guide

Buyers should order the report on the form their state requires. A box B finding calls for a treatment quote plus a structural assessment. Blocked areas should be opened and re-inspected, and a closing that slips past 90 days needs a new report.

Questions about Wood-Destroying Organism (WDO) Inspection

What is a WDO inspection for a house?

A WDO inspection is a visual check by a licensed inspector for termites and other wood-destroying pests, usually ordered when a house is sold or refinanced.

The inspector checks reachable areas, probes wood, notes evidence and damage, lists blocked areas and recommends whether treatment is needed. The result is a standard report such as the NPMA-33 or a state form.

What is the difference between a WDI and a WDO inspection?

WDI stands for wood-destroying insect and WDO for wood-destroying organism. The NPMA-33 is a WDI report: it covers termites, carpenter ants, carpenter bees and reinfesting wood-boring beetles, not fungi. WDO reports, such as California’s, also cover wood-decay fungus and dryrot. NPMA offers a model attachment where an area requires WDO reporting.

How long is a termite inspection report good for?

For a mortgage or a property sale, the NPMA-33 is invalid if not used within 90 days of the inspection date. The form states that this is not a 90-day warranty.

It describes conditions only on the day of the inspection, so a new infestation could start the next week and the report would not cover it.

Is a termite inspection required for an FHA or VA loan?

Sometimes. The NPMA-33 is approved for FHA and VA loans, and NPMA says it must be used for wood-destroying insect inspections in HUD and VA transactions unless a state mandates its own form. Whether one is required depends on the program, the area and what the appraiser sees. Ask your lender for the current rule.

What does box B mean on an NPMA-33?

Box B means the inspector saw visible evidence of wood-destroying insects. NPMA says it must be checked for any visible evidence, no matter how old or small.

At least one sub-box is then checked: live insects; dead insects, frass, tubes, exit holes or staining; or visible damage. The form advises a structural professional if damage is a concern.

Does a WDO inspection find hidden termite damage?

Not always. It is a visual inspection of readily accessible areas with probing and sounding of wood. The NPMA-33 says infestation and damage may exist in concealed or inaccessible areas, and the inspection firm cannot guarantee it found all of it. Nothing is torn open, so damage behind walls or under floors can be missed.

Who pays for the WDO inspection, buyer or seller?

It depends on the purchase contract, local custom and the loan program, so there is no single rule. Agree on it in writing before ordering.

Also agree on who pays for any treatment or repair if the report finds evidence.

The NPMA-33 says the inspection company is not responsible for treatment or repairs unless a separate contract says so.

Will the inspector treat termites if they find them?

Not as part of the inspection. The NPMA-33 says the inspection firm is not responsible for repairing damage or treating an infestation except under a separate contract. The report may recommend treatment, and a licensed company can then give a treatment plan and quote. A structural professional should judge any damage.

Does California use the NPMA-33?

Not for its required reports. California regulation 16 CCR §1996 requires wood-destroying organism reports under Business and Professions Code §8516(b) on Form No. 43M-41. That form includes findings for subterranean termites, drywood termites, fungus or dryrot, other findings and areas needing further inspection, and must be delivered even if the inspection was free.

What can I do before the inspection to help?

Clear access to the attic, crawl space, basement walls and garage. The NPMA-33 lists stored items, clutter, appliances and insulation as common obstructions, and crawl spaces with under 24 inches of clearance may be called inaccessible. Gather any past treatment records or warranty papers, since documented treatment can change the inspector’s recommendation.

Sources

National Pest Management Association, Form NPMA-33 Wood Destroying Insect Inspection Report (copy hosted by the Ohio Department of Agriculture), retrieved October 11, 2026.
National Pest Management Association, Suggested Guidelines for Completing the NPMA-33 (Version 1.3, 08/2019), retrieved October 11, 2026.
Georgia Structural Pest Control Commission, Notice 15-01: Official Georgia Wood Infestation Inspection Reports (Feb. 10, 2015), retrieved October 11, 2026.
Cal. Code Regs. tit. 16, §1996, Requirements for Reporting All Inspections Under Section 8516(b) (via Cornell LII), retrieved October 11, 2026.
U.S. EPA, Termites: How to Identify and Control Them, retrieved October 11, 2026.

Expert review

Written by the HyrePest Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.

How the numbers were checked: Scope, limits, sections, the 90-day validity and treatment recommendation rules are quoted from the NPMA-33 form and NPMA’s 2019 completion guidelines.

The state-form rule and HUD Mortgagee Letter 95-33 are from Georgia SPCC Notice 15-01. California requirements are from 16 CCR §1996. Signs and prevention follow the EPA termite page.

When FHA and VA require an inspection was not verified against current HUD and VA texts, so the page tells readers to ask their lender. Held for G-REV: a state-licensed WDO inspector should review before indexing.

Suggest a correction. We fix errors and say what changed.