A retirement winter now bears down on millions of Americans. For most, preparations remain inadequate. Myriad factors have contributed to this, many of them systemic.

Since the 1980s, the American retirement infrastructure has eroded as defined benefit plans disappeared and defined contribution plans fell short. The average American has no retirement savings, and those with 401(k)s and other retirement accounts have accumulated an average of just $40,000. We all want our golden years to be a time of peace when we enjoy time with family and pursue our dreams. In order for this to happen, pre-retirees must act now in creating a diversified retirement portfolio that ensures the financial stability needed for a dignified retirement.

How lack of diversification damages a retirement portfolio

Stocks may boast the largest returns over long time periods, but they also could lose the most when economic conditions deteriorate. Some stocks may go to the moon, but for each high-flyer there is at least one laggard, and total disasters like Enron happen more frequently than most investors like to think.

In the documentary "The Smartest Guys in the Room," viewers see Enron management encourage employees to invest 100% of their retirement savings in company stock. Most who did lost everything. This extreme example shows what can happen when a retirement portfolio lacks diversification.

Diversification means more than buying a variety of stocks. Investors must also diversify among asset classes. As retirement nears, the danger of sequence risk increases. Sequence risk is the possibility that the market will take a dive right before retirement, slashing portfolio values at the worst time, as happened to many pre-retirees during the 2008 meltdown. Asset class diversification could have saved many retirement plans during the Great Recession.

How to properly diversify a portfolio

To create portfolio diversification, consider balancing investment dollars between stocks, bonds, exchange-traded funds (ETFs), mutual funds and cash equivalents. Be open to having stocks, mutual funds and ETFs representing a range of growing industries, company sizes and global locations.

Other options are real estate investment trusts (REITS) for their high dividends. REITS and bond funds could become income streams during retirement. You could consider protecting yourself against sequence risk by placing some money into an annuity or universal life insurance policy that pays a return when markets go higher while guaranteeing your principal.

Taxpayers should be aware of all the retirement accounts available. Getty

What the coming "winter" means for a portfolio

A National Institute on Retirement Security study shows that 75% of Americans feel the nation faces a retirement crisis. The high cost of health care and long-term care coupled with rising costs of living have most Americans fearing that their portfolios are too small for the coming "winter." They are both right and wrong.

More savings are clearly needed. Those nearing retirement can shore up their savings by taking advantage of 401(k) and IRA catch-up contributions, which allow for additional tax-deferred savings. Seniors can also increase their Social Security income by working a little longer and delaying their benefits until they reach the full retirement age of 67. Those who must stop working before then for health reasons may gain access to disability benefits.

Pre-retirees can also prepare for retirement by creating a post-working-years budget. Taxes generally go down during retirement. Retirees could consider further reducing their expenses by downsizing their home and moving to a less expensive part of the country or even retiring abroad. By creating a budget based on a realistic but less expensive lifestyle, pre-retirees can gain confidence that their money will last.

The key to a secure retirement plan relies on a well-diversified portfolio that continues generating returns without exposing retirees to the risk of heavy capital losses. With careful planning and diversification, the retirement "winter" can turn into a summer at the beach.

(Rodger Parker is the CEO and President of Parker Financial Group, a leader in providing retirement planning services to individuals and families based in Overland Park, Kansas.)