That's one of the most important -- and most underestimated -- questions in retirement planning.

Longevity risk simply means the risk of outliving your money. And with life expectancy rising, it's no longer a theoretical problem -- it's a real one that can quietly compound every other financial risk: inflation, market volatility, healthcare costs, and taxes.

Let's walk through how to think about longevity risk from an educational standpoint -- and how retirees can design a plan that lasts well into their 90s or even 100s.

1. Understanding the math of longevity

The average life expectancy for a 65-year-old today is around 85 for men and 87 for women, but that's just the midpoint -- half of retirees will live longer.

• A healthy 65-year-old couple has about a 50% chance that one spouse will live past age 92, and a 25% chance one will live past 97. That means retirement could last 30-35 years, nearly as long as your entire working career.

So the question isn't just "Can I afford to retire?" -- it's "Can my plan adapt and sustain three decades of life changes?"

2. Building income that lasts a lifetime

The foundation of longevity planning is creating durable, predictable income -- income that continues for as long as you live, regardless of market performance.

You can think of your retirement income in two layers:

• Guaranteed income sources: Social Security, pensions, and certain types of annuities (such as lifetime income annuities or annuity riders). These provide stability and reduce pressure on your portfolio.
• Market-based income sources: Withdrawals from IRAs, 401(k)s, Roths, and brokerage accounts. These offer flexibility and growth potential but come with market risk.

Blending these two creates a balanced strategy -- guaranteed income for essentials, investment growth for inflation and long-term spending.

3. The role of withdrawal strategy

A safe withdrawal strategy is critical for longevity planning.

The traditional 4% rule -- withdrawing 4% of your portfolio annually -- was designed for 30-year retirements, but it must be adjusted for today's low-interest environment and longer life spans.

Modern approaches, like dynamic or guardrail strategies, adjust withdrawals based on market performance:

• Withdraw slightly less during bad markets.
• Allow modest increases during strong markets.

This flexibility significantly improves the odds that your portfolio lasts through a long retirement.

4. Keeping growth in the plan

One of the biggest longevity mistakes is becoming too conservative too soon. If all your money is in cash and bonds by your 60s, inflation can quietly erode purchasing power over 20-30 years.

Even in retirement, maintaining some equity exposure (often 40-60%) helps offset inflation and supports portfolio longevity -- especially when paired with smart withdrawal management.

5. Managing healthcare and long-term care

Healthcare costs rise with age, and they often peak in the later stages of retirement -- right when portfolio drawdowns can be hardest to replace.

• Consider Health Savings Accounts (HSAs), Medicare optimization, and possibly long-term care or hybrid insurance to protect against large, late-in-life expenses. Planning for these costs up front means your investment withdrawals remain sustainable longer.

6. Tax diversification extends longevity, too

It's not just about investment returns -- it's also about tax efficiency. By maintaining a mix of taxable, tax-deferred, and Roth accounts, you can control your taxable income each year. This helps:

• Reduce Medicare surcharges (IRMAA).
• Manage Required Minimum Distributions (RMDs).
• Keep your portfolio lasting longer by minimizing unnecessary taxes.

7. Planning for the surviving spouse

Longevity planning isn't just about your lifespan -- it's about your spouse's, too. When one spouse passes, household income often drops (for example, losing one Social Security check), but expenses don't drop by 50%.

Having guaranteed income sources that continue for both lives, or survivor benefits built into pensions and annuities, ensures stability for the surviving spouse.

8. Reassess regularly

Longevity planning isn't "set it and forget it." Review your plan every year or two to update spending, portfolio performance, health outlook, and tax laws. Small adjustments early can prevent major shortfalls later.

In summary

Living into your 90s is not just possible -- it's increasingly probable. The key is to design a plan that's resilient, not just optimistic.

A solid longevity strategy includes:

• Guaranteed lifetime income for essentials.
• Growth investments to offset inflation.
• A flexible, tax-efficient withdrawal plan.
• Protection against healthcare and long-term care costs.
• Periodic reviews and adaptability over time.

The goal isn't just to make your money last -- it's to ensure your quality of life lasts along with it. When planned correctly, living longer stops being a financial risk -- and becomes a blessing you can fully enjoy.