The vast majority of Americans want to remain in their homes throughout retirement, but a new study finds that 8 in 10 drastically underestimate the cost of getting the in-home help that many will need to make it possible.

The latest Genworth Cost of Care study finds that the median rate for a homemaker, who provides full-time help with household tasks, costs a median $3,861 per month, and a full-time home health aide costs a median $3,813 per month. Americans underestimate the costs for these services, the most popular care options, by almost 50 percent.

Over the past five years, homemaker costs have gone up 11.1 percent, and health aide costs have risen 6.6 percent. (Remember Tuesday’s post about inflation? These are the types of costs that are usually retiree specific, and why they are as a group experiencing inflation even when the government’s calculations say there is none!)

The survey also looked at the cost of other types of long-term care. The monthly cost of a private nursing room increased 1.24 percent to $7,698 (a shared room is $6,844). The cost of assisted living ticked up slightly to $3,628 per month.

At least 70 percent of Americans over age 65 will need some form of long-term care at some point in their lives. Medicare covers 100 days at a nursing home, and may cover home care for a short period of time, but most people must pay for them out-of-pocket or through long-term care insurance policies. So, with statistics like this, a plan for long-term care is becoming a necessary part of retirement planning.