Baby boomers and even younger workers planning for retirement might have to start actively setting aside money for medical costs, an escalating expense that many local financial experts say retirees often overlook.

A recent report from Fidelity Investments estimates that a 65-year-old couple retiring on Medicare will need at least $240,000 to cover medical costs throughout their retirement. The figure is 4 percent higher than in Fidelity’s 2011 report, which predicted retirees will spend $230,000 on medical expenses.

The increase comes at a time when 44 percent of people, mostly low-income earners, born between 1948 and 1964 are projected to lack adequate income for basic retirement expenses, including uninsured health care costs, according to a May report from the Employee Benefit Research Institute.