5 Common Retirement Planning Mistakes (and How to Avoid Them)

Most retirement shortfalls don't come from one dramatic bad decision — they come from a handful of quiet, avoidable habits that compound over decades, the same way good habits do. Here are five of the most common ones.

1. Leaving employer match money unclaimed

If your employer matches 401(k) contributions up to a certain percentage and you're contributing less than that, you're leaving guaranteed money on the table — often the single highest-return dollar available in your entire plan. This is usually the first thing worth fixing before optimizing anything else.

2. Underestimating how long retirement actually lasts

A 65-year-old today has a meaningful chance of living past 90. Planning around an assumed 15–20 year retirement, when it could easily run 25–30 years, is one of the most common ways plans fall short late in life. Modeling a longer horizon than you expect, rather than an average or optimistic one, builds in a margin of safety.

3. Being too conservative — or too aggressive — with investments

Shifting entirely to cash or low-yield holdings decades before retirement can quietly erode purchasing power to inflation. Going too aggressive close to retirement, on the other hand, leaves a portfolio vulnerable to a downturn right when withdrawals are starting. Both mistakes usually come from reacting to short-term market mood rather than following a plan matched to your actual time horizon.

4. Not accounting for healthcare costs

Healthcare tends to be one of the largest and most underestimated retirement expenses, particularly before Medicare eligibility and for long-term care needs that Medicare doesn't fully cover. A retirement budget that only extends recent healthcare spending forward, without a buffer, is often optimistic.

5. Never actually checking the numbers against a target

It's easy to save "as much as feels reasonable" for years without ever comparing that amount against what you'll actually need. Small shortfalls are easy to close a decade in advance; the same shortfall discovered the year before retirement leaves far fewer options. Checking your projected savings against your target periodically — not just once — is what actually catches a gap while there's still time to close it.

A quick way to check where you stand

Our retirement and FIRE calculator lets you run exactly this comparison: a target nest egg based on your desired retirement income, checked against your projected savings given your current contributions and timeline, with the monthly increase needed to close any gap.

This article is for educational purposes only and is not financial advice. Consult a licensed financial advisor for guidance specific to your situation.