Fifty first-time millionaires recently revealed the retirement mistakes they wish they'd avoided. Their insights offer practical lessons for anyone approaching retirement.

The millionaires stressed the importance of healthcare planning. Many underestimated medical costs in retirement, which can easily drain $300,000 or more over a 30-year retirement. They recommend getting detailed cost estimates early and exploring Medicare supplement plans like Medigap or Medicare Advantage options before age 65.

Social Security timing emerged as another common regret. Several millionaires claimed benefits too early at 62 and lost substantial lifetime income. Delaying to age 70 increases monthly payments by roughly 24 percent per year. Those in good health often benefit from waiting, gaining an extra $50,000 to $100,000 or more over their retirement years.

Tax strategy ranked high on the regret list. The millionaires wished they'd worked with tax professionals to minimize withdrawals from taxable accounts and structure Roth conversions strategically. Poor sequencing of retirement account withdrawals created unnecessary tax bills that reduced their portfolios' growth potential.

Many also regretted not diversifying their wealth beyond real estate or a single investment. Concentrated positions in company stock or rental properties created unnecessary risk. A balanced portfolio spanning index funds, bonds, and dividend stocks would have provided more stability and flexibility.

Finally, the millionaires emphasized the value of lifestyle planning. Some retired without clear hobbies, travel plans, or volunteer work. Retirement felt aimless. Those who thrived had structured their time around meaningful activities and maintained social connections.

The common thread: financial success requires planning beyond simply accumulating wealth. Healthcare costs, tax efficiency, Social Security timing, and diversification matter enormously. Equally important is building a retirement life that feels purposeful, not just profitable. Start these conversations with a financial advisor and tax specialist