modified reserves (full preliminary term, Zillmer)
/ TSILL-mer /
A brand-new policy is expensive: the agent's commission and underwriting eat up much of the first year's premium, so almost nothing is left to build the reserve. Yet a strict net-premium reserve pretends the customer paid the full expense-free net premium and demands a reserve be set up immediately — which can force a young, capital-light insurer to find money it does not yet have. Modified reserves are a family of methods that bend the reserve schedule to reflect this reality: hold a smaller reserve in the first year, then make it up over the following years.
Precisely, modified reserve methods replace the level net premium with a non-level 'valuation premium': a lower premium assumed in year one (so most of the first premium can go to expenses) and a slightly higher level premium thereafter, chosen so the present values still balance. Full preliminary term (FPT) is the extreme case: it treats the first policy year as a pure one-year term insurance, making the first-year reserve essentially zero. The Zillmer method is a gentler version: it allows only a limited 'Zillmer adjustment' for expenses, so the reserve is reduced in early years but not all the way to zero. Both converge to the ordinary net premium reserve in later durations.
Modified reserves matter because they reconcile honest first-year expense strain with the legal duty to hold reserves, and they historically eased the capital burden of writing new business. The honest caveat: a modified reserve is deliberately LOWER than the net premium reserve in the early years, so it provides less of a cushion just after issue. Regulators therefore cap how much modification is allowed (e.g., limiting the Zillmer adjustment), and a heavily modified reserve must never be confused with a more conservative one.
Under full preliminary term, the first year is valued as one-year term insurance, so the year-1 reserve is about zero and the agent's commission can be paid from the premium. The valuation premium for years 2 onward is then a touch higher than the ordinary net premium, repaying the deferred build-up.
Modify the premium schedule so year-1 expenses are funded; reserve catches up later.
A modified reserve is intentionally smaller than the net premium reserve in early years — it is less conservative, not more. Regulators cap the modification for exactly this reason.