When it comes to making retirement plans, chances are good you're dreaming of all the fun things you can do once you no longer have to go to work. But while you may be making a hefty travel budget or plotting all the spending you'll do to spoil the grandkids, chances are good there are some important expenses you're overlooking.

Sadly, these costs can derail your carefully laid plans if you aren't prepared for them. To ensure that doesn't happen to you, it's essential you factor in these three big expenses you're likely to incur as a retiree when you're setting retirement savings goals.

Broken white piggy bank with coins spilling out.

Image source: Getty Images.

1. Healthcare

The sad reality is that the aging process often leads to an increase in health problems. Despite that, fewer than a third of Americans have made an attempt to determine the amount of money they'll need for healthcare in retirement. That's a big problem since the amount of money that seniors may need is shockingly high. Some researchers estimate that a senior couple retiring in 2020 who require a lot of prescription drugs could incur out-of-pocket expenses of around $325,000 throughout retirement. 

Some pre-retirees may be neglecting to plan for care costs because they think Medicare will have them covered. But while Medicare pays for most hospitalizations, as well as some outpatient care, there are big coverage gaps, as well as high coinsurance costs for outpatient services.

Seniors will absolutely need supplementary savings earmarked for medical expenses if they don't want to drain their nest egg. Those who have access to a health savings account (HSA) should consider using it to invest for their medical needs in retirement, due to the tax benefits it provides. But those who aren't eligible for an HSA need to invest more in a 401(k) or IRA specifically to cover the medical expenses they'll likely incur. 

2. Long-term care

LongTermCare.gov has a dire warning for retirees: You'll probably spend some time in a nursing home or being cared for at home in the future. In fact, if you're turning 65 now, you have close to a 70% chance of requiring this type of assistance at some time during your lifetime. And around 20% of today's 65 year olds may need more than three years of long-term care in a nursing home or provided at home. 

Chances are good that you aren't planning for that when you think about retirement, and that's a huge issue since Medicare won't pay for nursing home or home health services under most circumstances. With long-term care services costing thousands of dollars a month, you could run through your entire savings balance in the blink of an eye, leaving your spouse with little to live on or draining any inheritance you hoped to provide your loved ones. 

Preparing for big long-term care bills is tricky because the expense is just so high, it's hard to save enough. Still, you can earmark money in investment accounts for potential future nursing home care. You can also look into long-term care insurance, but be sure to research policies carefully, as some provide more comprehensive coverage than others.

3. Family support

While retirement allows you to give up working for a paycheck, you probably can't retire from your family responsibilities. In fact, millions of seniors still provide financial support to adult children. And some retirees still have caregiving responsibilities for aged parents or are caring for spouses or siblings -- which can come at a huge financial and personal cost. 

Chances are good you aren't going to cut off your children or stop helping family members who need it just because you're retired. But if you're barely getting by yourself, you could end up draining your nest egg too quickly if you provide this kind of support.

If you plan to be generous with your loved ones in your later years, build some extra money into your retirement savings plans to allow you to do that without jeopardizing your own financial stability.