The good news: Through hard work, thrift, and wise choices, you’re set for retirement. The bad news: You might find it harder someday to make sound financial decisions. On average, money smarts peak at age 53, the Center for Retirement Research reported in 2010. The older you get, the greater your vulnerability to scams, unscrupulous advisers, or just poor judgment.

The stakes are high: Fraud victims 65 and older lost an average of $30,000, Allianz found last year. One in 10 lost more than $100,000.

In my latest for Money magazine, I discuss measures to take that can protect your finances, or the finances of a parent or older relative.