Your 40th birthday marks a natural checkpoint for financial health. The decisions you make before hitting that milestone shape your comfort during your peak earning years and retirement security.

Max out your retirement contributions. If you earn $70,000 annually, you can contribute $23,500 to a 401(k) in 2024. Those in their 50s gain catch-up contributions of an extra $7,500. If you're self-employed, a Solo 401(k) lets you save up to $69,000 annually. Starting now rather than waiting gives compound growth a full decade to work in your favor. Even modest increases in contribution percentages deliver outsized returns by retirement.

Build an emergency fund covering six months of expenses. Most people fall short with three months saved. Calculate your monthly expenses, then multiply by six. That number should sit in a high-yield savings account earning 4.5-5.35% annual percentage yield. Marcus by Goldman Sachs, Ally Bank, and American Express Personal Savings all offer competitive rates. This fund protects you from debt when job loss or medical emergencies hit.

Review your insurance coverage. Term life insurance costs roughly $25-40 monthly for a $500,000 policy if you're healthy and in your 30s. Waiting until 40 raises that premium by 40-50 percent. Disability insurance replaces 60-70 percent of income if you cannot work. Your employer may offer it for $15-30 monthly.

Eliminate high-interest debt. Credit cards charging 18-24 percent APR drain wealth faster than any investment builds it. Paying $5,000 at 20 percent APR costs you $1,000 in interest alone over two years. Aggressively pay down balances before age 40.

Reassess your asset allocation.