Should You Index Your Life Insurance to Inflation in NZ? (2026 CPI Indexation Guide)

Most NZ life policies offer to lift your sum insured each year in line with CPI. Here is how indexation works, why fixed cover quietly shrinks, what it does to your premium, and when declining the increase makes sense.

Once a year, most New Zealand life insurers send a letter offering to lift your sum insured in line with inflation, with a matching rise in premium. You can usually accept it or decline it. It looks like a small piece of admin, and it is easy to decline on autopilot to keep the premium down. Over a 20 or 30-year policy, that choice quietly decides whether your cover still does its job.

This guide explains what CPI indexation is, why a fixed sum insured shrinks in real terms, what accepting does to your premium, when declining can make sense, how it interacts with level versus stepped premiums, and the risk of declining year after year. It is general information about how indexation works — not a recommendation about your own policy.

TL;DR: Most NZ insurers offer an annual CPI increase to your sum insured, with a matching premium rise; you can usually decline it each year ⁷. CPI ran at 3.1% in the year to March 2026 ¹, so un-indexed cover loses a few percent of its real value annually and compounds to a real shortfall over decades. Whether to accept depends on your need, budget and premium structure — not on the letter alone.

What is CPI indexation on a life policy?

CPI indexation — sometimes called inflation adjustment, indexation benefit or automatic increase — is an option on most New Zealand life, trauma and other personal risk policies that lifts your sum insured each year so the cover keeps pace with rising prices. CPI stands for the Consumers Price Index, the measure Stats NZ uses to track how much the cost of everyday goods and services changes over time.

Here is the mechanism. Each year, around your policy anniversary, the insurer offers to increase your sum insured — typically by the latest annual CPI figure, often subject to a minimum floor such as 2–5% ⁷. Your premium rises to pay for the extra cover. You can accept the increase, or decline it for that year without affecting the cover you already hold ⁷. Most insurers — Asteron Life, Partners Life, AIA and Fidelity Life among them — build this in as a standard benefit ⁷.

A couple of points cause confusion and are worth being precise about:

• Indexation lifts the cover amount, not just the price. You are buying more cover each year, which is why the premium goes up — it is not a fee increase for the same protection.
• It is usually automatic unless you opt out, and a minimum floor can apply. Many policies index by default, so declining is an active choice each year. Some index by the greater of CPI or a fixed percentage (often 2–5%), so in a low-inflation year the increase may exceed headline CPI ⁷.

Why does fixed cover shrink in real terms over time?

A sum insured fixed at one level buys less protection each year because prices keep rising. The dollar figure on your policy stays the same, but what it can pay for — a mortgage, years of household income, childcare, a funeral — costs more over time. This is inflation eroding the real value of the cover.

The scale is easy to underestimate. CPI inflation was 3.1% in the 12 months to the March 2026 quarter, just above the top of the Reserve Bank's target band ¹. The Reserve Bank of New Zealand targets annual CPI of 1% to 3%, focused on a 2% midpoint ³ — and even at that 2% midpoint, un-indexed cover loses about 2% of its real value every year, compounding to a material shortfall over a 20 to 30-year policy. Inflation is not always mild, either: annual CPI peaked at 7.3% in the June 2022 quarter, its highest in over three decades, which would cut roughly 7% off a fixed sum insured in a single year ².

The domestic side of inflation tends to drive how much cover a household actually needs. Over the year to March 2026, non-tradeables (domestic) inflation ran at 3.5%, faster than the 2.5% tradeables (imported) rate ⁵ — and domestic costs like housing, rates and services are exactly the ones a life payout has to cover. Because inflation compounds, the effect over a policy's life is larger than any single year suggests: with CPI running roughly 3% to 7.3% a year across 2022–2026 ⁶, a sum insured fixed at its 2020 level buys substantially less protection in 2026. That compounding is the core reason most insurers offer indexation in the first place ⁶.

!Line chart showing the nominal sum insured of $500,000 staying flat over 20 years while its real purchasing power declines each year as CPI erodes it, leaving a widening gap between the cover on paper and what it can actually buy.

Figure: Real value of $500,000 of un-indexed cover over 20 years (illustrative). The nominal sum insured stays flat while CPI erodes its purchasing power each year, opening a widening gap between the cover on paper and what it buys. Source: illustrative, based on Stats NZ CPI ¹⁶. Projections are illustrations based on stated assumptions, are not predictions, and actual results will differ.

What happens to your premium when cover indexes up?

When you accept the annual increase, you are buying more cover, so the premium rises to match. The increase pays for the extra slice of sum insured, priced at your current age. Decline it and your premium stays where it is for that line of cover — but so does your sum insured, which then falls behind inflation again. The size of the rise depends on how the increase is priced and on your premium structure (more below). Because the indexed increase layers on top of any age-based increase you already face, an indexed premium can climb noticeably faster than a fixed-sum one ⁷⁸.

The trade-off is worth stating plainly. Accepting indexation keeps your cover matched to rising costs, but lifts your premium every year and can make cover dearer to hold later in life. Declining keeps the premium down today, but lets the real value of your protection erode. Neither is automatically right — it depends on whether you still need the higher cover, and what you can comfortably afford now and later.

When does it make sense to decline the increase?

Declining the CPI increase is a legitimate choice in several situations — it is not simply giving up. It can make sense when:

• Your need is genuinely falling. As a mortgage shrinks and children become independent, the cover a household needs often reduces. If your need is dropping faster than inflation erodes the cover, declining (or actively reducing cover) can be reasonable.
• The premium is becoming unaffordable. Cost is the most common reason cover lapses, and a policy you cancel because the indexed premium outgrew your budget protects no one. A slightly lower but affordable level of cover can beat losing it entirely.
• Other cover already does the job. If a separate policy, a payout, an inheritance or growing savings fills the gap, indexing every policy on top may be more cover than you need.
• You are close to dropping the cover anyway. If you expect to cancel within a year or two, paying for an increase you will not hold for long adds little.

The opposite case — where accepting tends to make sense — is when your need is steady or rising, your budget can absorb the increase, and you want the cover to keep its real value over the long term without re-underwriting later. Importantly, declining is not the same as reducing: decline several years running, then decide you need more cover, and topping it back up usually means fresh underwriting (covered below).

This is general information, not a recommendation about your own policy. Working out whether your need is actually falling is part of a wider review — our guide on how much life insurance you need walks through the inputs.

How indexation interacts with level vs stepped premiums

Indexation behaves differently depending on whether your premium is stepped or level, and this is one of the more important interactions to understand before you decide.

On a stepped premium — repriced to your age each year — the indexation increase layers on top of the age-based annual rise ⁸. Two things lift the premium at once: you are a year older, and your sum insured is larger. The two stack, so an indexed stepped premium can climb a good deal faster than a stepped premium on a fixed sum insured.

On a level premium — locked to your age at application — the original sum insured keeps its level pricing, but each annual indexed top-up is usually added as a new layer priced at your current age ⁸. The bulk of your cover stays on the locked-in level rate, so the compounding is gentler. The trade-off is that repeatedly accepting increases can blunt some of the cost advantage you took level cover to capture, because each new slice is priced at an older age.

Figure: How CPI indexation interacts with each premium structure. Source: Smiths Financial summary of NZ insurer premium structures, based on FMA life insurance guidance ⁸; general structure, not a quote.

There is more on choosing between the two structures in our guide on level vs stepped premiums.

The risk of repeatedly declining the increase

Declining once, in a year where your need has genuinely fallen, is usually harmless. The risk is declining year after year out of habit, because the cumulative gap compounds quietly until your cover no longer matches what it was bought to protect.

Two specific traps are worth naming. First, the erosion is invisible until you claim. The dollar figure on the policy never changes, so nothing prompts you to notice it now covers a smaller share of your mortgage or fewer years of income than it did. The shortfall only surfaces at the worst possible moment — at claim time.

Second, topping the cover back up later usually means re-underwriting. If you decline for years and then realise you are under-covered, increasing the sum insured generally requires fresh medical and financial underwriting, and whether it is offered depends on your health, age and disclosure at the time ⁷. A condition that has developed in the intervening years can mean the top-up is loaded, excluded or declined. Indexation, by contrast, typically increases cover without fresh underwriting — part of its value for people whose health may change.

Some insurers also limit how many times you can decline before the indexation option drops off, after which reinstating it means re-applying. The details vary by policy and sit in the wording, which is one reason a periodic review beats reacting to each annual letter in isolation. Old policies are especially worth checking — our guide on reviewing an old life insurance policy covers what to look for.

How an adviser keeps your cover matched to your needs

The annual CPI letter is a yes/no decision made in isolation, usually without reference to whether your actual need has changed. A review reframes it: instead of accepting or declining on autopilot, you decide based on what your household needs now and what you can afford.

In practice that means estimating your current need — debts, income to replace, dependants, existing cover and other assets — and comparing it with your sum insured to see whether it is keeping pace, lagging, or already higher than required. From there the indexation decision follows the need: accept where cover should keep growing, decline or actively reduce where the need is falling, and factor in your premium structure and budget so the cover stays affordable enough to keep. Sometimes the answer is to index some policies and not others.

We're generally paid by commission from the insurer when you take out a policy through us; this doesn't change the premium you pay, and any conflicts of interest are managed in line with our duty to prioritise your interests — full details are in our disclosure. A review is not about pushing you to accept every increase; it is about making sure the cover you pay for still matches the job it was bought to do.

Frequently asked questions

Should I accept the annual CPI increase on my life insurance?

It depends on whether you still need the higher cover and what you can afford. Accepting keeps your sum insured matched to rising prices but lifts your premium each year; declining keeps the premium down but lets the real value of the cover erode ¹⁷. This is general information, not personalised advice.

What is indexation on a life insurance policy?

Indexation, or CPI/inflation adjustment, is an option on most NZ policies that increases your sum insured each year in line with the Consumers Price Index, often subject to a minimum floor such as 2–5%, with a matching premium rise ⁷. You can usually accept or decline the increase each year without affecting the cover you already hold ⁷.

How much does inflation reduce my cover if I decline?

Roughly in line with CPI each year. CPI was 3.1% in the year to March 2026 ¹, and even at the Reserve Bank's 2% midpoint, un-indexed cover loses about 2% of its real value annually ³. Because inflation compounds, a sum insured fixed in 2020 buys substantially less in 2026 ⁶.

Does accepting indexation require new medical checks?

Usually not. Indexation typically increases your cover without fresh underwriting, which is part of its value ⁷. By contrast, if you decline for years and later try to top your cover back up, that increase generally does require new medical and financial underwriting, and may be loaded, excluded or declined depending on your health at the time ⁷.

Is it better to decline indexation if I have level premiums?

Not necessarily. On level cover the core sum insured keeps its locked-in rate, but each indexed top-up is added at your current age, which can blunt some of the level cost advantage over time ⁸. Whether to accept depends on your need, your budget and how long you will hold the cover — an adviser can model it across your timeframe.

How often should I review whether my cover is keeping up?

Many people review around each annual policy anniversary, when the CPI letter arrives, and after major changes — a new mortgage, a child, a pay change or a health event. This is general information; to check your cover still fits, book a review.

This article is general information only and is not personalised financial advice. It does not take into account your particular financial situation, goals or needs. Before acting, consider whether it's right for you and seek advice tailored to your circumstances. Whether a claim is paid depends on the terms, conditions, exclusions, stand-down periods and underwriting of the specific policy, and on your disclosure — this is a summary only, always read the policy wording. Projections are illustrations based on stated assumptions, are not predictions, and actual results will differ. 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). Written by Henry Smith, Financial Adviser; reviewed by Craig Smith, Principal Adviser. Last reviewed 4 May 2026.