How Health Insurance Underwriting Works in NZ (2026): What Insurers Ask and Why

When you apply for health insurance in NZ, the insurer underwrites your application — asking about your health, lifestyle and family history. Here is what they ask, why it matters, and how to disclose correctly so your cover holds up at claim time.

When you apply for health insurance in New Zealand, the insurer does not simply hand you a policy. First it underwrites your application — it asks about your health, lifestyle and family history, and decides whether to accept you, and on what terms. For most people this is the part of the process they understand least, and it is also the part that determines whether a future claim gets paid.

This guide walks through what underwriting is, the questions insurers ask and how far back they look, the legal duty you have to tell them the truth, and the outcomes you might receive. The single most important idea to carry through it: what you disclose at application is what protects you at claim time.

TL;DR: Underwriting is how an NZ insurer assesses your health risk before offering cover. You have a legal duty to disclose anything relevant to that decision — not just diagnoses. Outcomes are usually one of four: accept on standard terms, a premium loading, an exclusion, or a decline or deferral. ¹⁵ Get disclosure wrong and the insurer can refuse all or part of a claim. ²

What is health insurance underwriting, and why does it exist?

Underwriting is the process an insurer uses to assess the risk you bring before it agrees to cover you. It looks at health conditions, lifestyle factors and family medical history, then prices and structures your policy so the cost is shared fairly across everyone in the pool. ⁶ If your application suggests a higher likelihood of claiming, the insurer may respond with an exclusion, a higher premium, or by declining to offer cover at that point in time. ⁶

The reason it exists is the cost it is designed to manage. Southern Cross, New Zealand's largest health insurer, paid $1.45 billion across 3.2 million claims in 2024, with an average cost per claim of $468 — up 44% from $324 in 2020. ⁸ Across the market, the number of New Zealanders with health insurance has risen to about 1.45 million, with 37% of people surveyed reporting they hold cover, up from 32% the year before. ⁷ Underwriting is the mechanism that keeps a growing, more expensive pool sustainable for everyone in it.

It is worth knowing the limits insurers work within. A private medical insurer in NZ may underwrite — asking about health, lifestyle and family history — but cannot refuse cover solely because of your age or disability. ⁹ It can, however, apply waiting periods or exclude specific health conditions. ⁹

What questions do insurers ask, and how far back?

Application questions vary by insurer, but they cluster into a few predictable areas. The table below shows the common categories and why each one matters to the underwriter.

How far back the questions reach depends on the insurer and the question. Some focus on recent years; others ask about anything that has ever occurred. The safe approach is not to guess the boundary. If a question asks about your medical history without a stated time limit, treat it as covering your whole history.

A point many people miss: you are not only being asked about formal diagnoses. Consumers often know to disclose a diagnosis but not an undiagnosed sign or symptom — and undisclosed symptoms are a common reason claims later fail. ³ A pain you mentioned to your GP, a test you were waiting on, a lump you were keeping an eye on — these can all be relevant even if no doctor has named a condition.

What is the duty of disclosure, and what happens if you get it wrong?

In New Zealand you have a legal duty of disclosure. You must tell the insurer everything relevant to its decision to accept the risk and on what terms — including information it did not specifically ask about — when you take out, renew or vary your cover. ¹

This duty matters because of what happens when it is breached. If you do not disclose something you should have, the insurer may refuse to pay part or all of a claim, or treat the policy as if it never existed (avoid the contract from the start). ² Deliberate non-disclosure or a false answer is insurance fraud, which is a crime. ²

There is a harder edge to the current law worth understanding. Under the rules that applied as at 20 June 2025, non-disclosure of material information could let an insurer avoid the contract and refuse a claim even where the undisclosed fact had no connection to what you were claiming for. ³ In other words, an unrelated omission on your application could still cost you an unrelated claim. That is why under-disclosing is far riskier than over-disclosing.

Is the law on disclosure changing?

Yes. The Contracts of Insurance Act 2024 reforms this area. It replaces the broad disclosure duty with, for consumers, a duty to take reasonable care not to make a misrepresentation, and a fair presentation of the risk duty for non-consumer contracts. ⁴ The Act was passed but its main provisions had not yet commenced as at 20 June 2025, with main commencement set for 15 November 2025. ⁴ Until then, the existing common-law duty still applies — so the practical advice for anyone applying now is unchanged: disclose fully rather than guess. ⁴

Loading, exclusion or decline: the possible outcomes

Once the insurer has assessed your application, the decision usually falls into one of four outcomes. ⁵

For pre-existing conditions specifically, NZ insurers commonly use one of three levers: exclude treatment related to the condition, charge a higher premium, or apply a waiting or moratorium period before the condition is covered. ⁹ Which lever you get depends on the condition, how well it is managed and documented, and the insurer's own appetite. The same history can land very differently across insurers, which is one of the main reasons people compare before applying.

If you want to see how those pre-existing-condition outcomes work in detail, including continuous-cover pathways that can convert an exclusion into cover over time, our guide to pre-existing conditions and your insurance options goes deeper.

The underwriting decision tree below shows how an application flows through to one of those four outcomes, with the duty of disclosure sitting over the whole process.

Figure: the underwriting decision tree

``` APPLICATION │ ┌───────────────┴───────────────┐ ▼ ▼ Medical questions Pre-assessment (full disclosure) (test the waters first) │ │ └───────────────┬───────────────┘ ▼ UNDERWRITER ASSESSES │ ┌──────────┬────────┴────────┬──────────┐ ▼ ▼ ▼ ▼ Accept Load Exclude Decline / (standard) (higher (condition Defer premium) carved out)

┌───────────────────────────────────────────────────┐ │ DUTY OF DISCLOSURE applies throughout. Get it │ │ wrong and a claim can be refused — even if the │ │ omission is unrelated to the claim. <sup>123</sup> │ └───────────────────────────────────────────────────┘ ```

Source: Provider PDS and FMA guidance, 2026.

Why honesty at application protects you at claim time

It can be tempting to leave something off an application — a minor condition that feels irrelevant, a symptom you would rather not explain, or something that might push the premium up. The problem is that the application is the document the insurer relies on if you ever claim.

When a claim comes in, the insurer can review your medical records. If they find a condition, symptom or history that should have been disclosed and was not, the consequences flow directly from the duty above: the claim can be reduced or refused, and the policy can be voided from the start. <sup>2</sup> Under the law applying in mid-2025, that could happen even where the undisclosed item had nothing to do with the claim itself. <sup>3</sup>

The reassuring side of this is that full disclosure works in your favour. If you disclose a condition and the insurer accepts it — on standard terms, with a loading, or with an exclusion written in — you know exactly where you stand. There is no nasty surprise waiting at claim time, because the insurer already assessed the risk and priced it. A policy that has been honestly underwritten is a policy you can rely on. That is the whole point of getting this part right.

How an adviser helps you disclose correctly

Disclosing well is harder than it sounds. The questions can be broad, the relevance of an old or minor issue is not always obvious, and people genuinely differ in what they remember to mention. This is where working with an adviser changes the experience.

An adviser helps you in a few practical ways:

• Reading the questions properly. They help you understand what each question is actually asking, so you neither leave out something material nor over-complicate a simple answer.
• Building a complete history. Walking through your conditions, medications, tests and symptoms methodically tends to surface things you would otherwise forget.
• Matching you to the right insurer. Because outcomes differ across the market, an adviser compares insurers and places your application where your history is most likely to be accepted on good terms. How that comparison works is covered in our piece on how advisers compare insurers.
• Advocating at claim time. When a claim touches a disclosed condition, an adviser can help argue your corner against the policy wording.

We are an independent firm — we do not sell our own health insurance product. We compare cover across the major NZ insurers and place your application where it is most likely to succeed. If you are weighing up whether to hold medical cover at all, the importance of medical insurance sets out the case and the trade-offs.

Pre-assessment: testing the waters before you apply

One of the most useful tools in this process is pre-assessment. Before you submit a formal application, an adviser can put an anonymised summary of your health history to one or more insurers and ask, in effect, "what terms would you offer?"

This matters because a formal application creates a record. A declined or heavily loaded application can follow you and complicate future applications elsewhere. Pre-assessment lets you understand the likely outcome — standard terms, a loading, an exclusion or a decline — before anything goes on record. You can then apply where the terms are best, so your first formal application is also your strongest.

Pre-assessment does not bind the insurer to a final decision, and the formal underwriting still applies once you apply. But for anyone with a health history, it removes much of the guesswork and the risk of a poorly-placed application.

Frequently asked questions

What does underwriting mean for health insurance in NZ?

Underwriting is how an insurer assesses your health risk before agreeing to cover you. It reviews your health conditions, lifestyle and family medical history, then decides whether to accept you on standard terms, charge a loading, exclude a condition, or decline or defer cover. <sup>56</sup> The purpose is to price and structure cover fairly across everyone in the pool.

What questions do health insurers ask?

Insurers typically ask about your current health and medications, your past medical history (diagnoses, surgeries, tests), any symptoms you have noticed, lifestyle factors such as smoking and weight, and your family medical history. <sup>6</sup> Many questions are not limited to recent years, so it is safest to treat them as covering your full history.

Do I have to disclose conditions the insurer didn't specifically ask about?

Under the duty of disclosure that applied as at 20 June 2025, yes — you must tell the insurer everything relevant to its decision to accept the risk and on what terms, including information it did not specifically ask about. <sup>1</sup> This is changing under the Contracts of Insurance Act 2024 (main commencement 15 November 2025), but until then the existing duty applies. <sup>4</sup>

What happens if I don't disclose something?

If you breach the duty of disclosure, the insurer may refuse to pay part or all of a claim, or treat the policy as if it never existed. <sup>2</sup> Under the law applying in mid-2025, this could happen even where the undisclosed information was unrelated to the claim. <sup>3</sup> Deliberate non-disclosure or a false answer is insurance fraud, which is a crime. <sup>2</sup>

What is a pre-assessment, and should I do one?

A pre-assessment is an informal enquiry to one or more insurers, before a formal application, to gauge the terms they would likely offer based on your health history. It is especially useful if you have a health history, because it lets you understand likely outcomes without creating a formal record, so you can apply where the terms are best.

Can an insurer decline me because of my age?

No. A private medical insurer in NZ cannot refuse cover solely because of your age or disability. <sup>9</sup> It can, however, apply waiting periods or exclude specific health conditions based on its underwriting assessment. <sup>9</sup>

General information, not personalised financial advice. It does not take into account your particular financial situation, goals or needs. Consider whether it is right for you and seek advice tailored to your circumstances before acting. Whether a claim is paid depends on the terms, conditions, exclusions, stand-down periods and underwriting of the specific policy, and on your disclosure — always read the policy wording. Craig Smith Business Services Ltd (FSP712931), trading as Smiths Financial, holds a Class 2 licence issued by the Financial Markets Authority and is a member of the Financial Dispute Resolution Service (FDRS). We are generally paid by commission from the insurer when you take out a policy through us; this does not change the premium you pay. Written by Henry Smith, Financial Adviser; reviewed by Craig Smith, Principal Adviser. Last reviewed 20 June 2025.