⚠ The Increase Is Already Behind ItModerate threat

The trouble with a fee increase is that it is a step, not a slope. Costco's September 2024 rise contributed about 40% of membership income growth in fiscal 2025, about 35% across the first thirty-six weeks of fiscal 2026, and about 25% in the third quarter alone¹ — a decaying contribution, exactly as the deferral accounting predicts, heading to zero.

From here, membership fee growth has to come from members rather than from price: new sign-ups, and upgrades from the $65 tier to the $130 one. Both are real and both are working — total paid memberships reached 82.9 million at the third quarter of fiscal 2026 from 79.6 million a year earlier² — but neither is as easy as a price rise, and both are constrained by the same thing, which is how many suitable warehouse locations exist in markets that can support them.

There is a second-order effect worth naming. Because the fee rise flatters membership growth for roughly two years and then stops, the comparison in the third year is against an inflated base. Costco has been here before and has managed the transition without drama each time, but the arithmetic means the cleanest read on underlying membership health arrives about two years after each increase — which is to say, in fiscal 2027.

If membership fee revenue growth falls to the rate of paid-member growth and stays there while Executive penetration flattens, the pricing lever has been fully used and the next one is five or six years away.