Data Driven look at the impact of upcoming KiwiSaver contribution increases

The landscape of retirement savings in New Zealand is undergoing a structural transformation. Following the Budget 2025 announcements, the default settings for KiwiSaver are increasing to a higher baseline of 3.5% for both employer and employee contributions in April 2026. This is followed by a further increase to 4% from 1 April 2028.

To understand the magnitude of this change, we must separate the immediate impact on take-home pay from the long-term compounding effect on retirement wealth. Using the Financial Markets Authority (FMA) standard projection assumptions, which include a 3.5% annual salary growth and specific net return rates for different fund types, the data reveals a significant divergence in outcomes.

For a typical 25-year-old investor with a starting balance of $20,000, earning $70,000, the transition from the old 6% total contribution model to the new 8% total model (phased in by 2028) can result in a projected retirement balance that is hundreds of thousands of dollars higher.

The impact is visible across the entire risk spectrum. In a Conservative portfolio, which the FMA assumes returns 2.5% net, the step-up to 4% contributions is projected to add approximately $174,000 to a 40-year outcome compared to the old 3% settings. In an Aggressive portfolio, assuming a 5.5% net return, that same contribution increase could result in an additional $307,000 at retirement. These figures highlight that while market returns are a critical driver of wealth, the "savings rate" remains one of the most powerful levers an investor can pull. The Retirement Commission’s analysis suggests that for median earners, these changes could result in retirement funds lasting approximately 30% longer than under previous settings.

For advisers, this data provides a natural opening for deeper client engagement. The "forced" nature of these increases acts as a powerful nudge, helping to overcome the inertia that often keeps investors at minimum contribution levels. However, it also necessitates a review of fund suitability. As the volume of contributions increases, the "cost of being in the wrong fund" grows in absolute dollar terms. A client in a Conservative fund who should be in Growth is now missing out on a larger pool of potential compounding returns. By framing the 2026 and 2028 increases as a "future pay rise for your retired self," advisers can help clients visualise the tangible benefits of this policy shift.