Millionaires are like other people — they put off planning for what happens after they die. More than a third of them, in fact, “have not used a financial expert” to set up an estate plan, CNBC.com reports.

Estate planning encompasses many issues, from providing for heirs to critical end-of-life decisions, and includes issues related to property management, asset protection, potential cognitive or physical disability and more, experts tell the news website.

Changes in federal estate-tax hurdles, which up to 2013 saw a decade of flux and uncertainty, have driven high-net-worth individuals into “estate-planning fatigue,” experts tell CNBC.com. And that’s unfortunate, the same experts say, because many wealthy families fail to grasp that estate planning is about more than taxes.

Thirty-eight percent of people with $1 million or more in investable assets have no estate plans, according to a Spectrem Group poll of 750 millionaires conducted for CNBC. Those with $5 million or more are only slightly more likely to have estate plans (68%) than those who have $1 million to $5 million (61%). And — to give the issue a political spin — Republicans are only slightly more proactive (68%) than Democrats (61%) or independents (58%), according to the poll.

Not planning for the worst can result in “complete chaos,” says one of CNBC.com’s sources, an attorney and financial planner. And even where plans are in place, tax-code changes — the thing is always evolving — require high-net-worth individuals to revisit their estate plans on a regular basis. Recent tweaks, for example, suggest it may be advantageous from a tax viewpoint to leave money to heirs outright rather than have them collect income from property, another planner tells the website. Financial planners can help wealthy clients steer their assets into LLCs or family partnerships to protect them and their heirs from excessive tax obligations, the website adds.