If you decide you want it later, you'll have to pay a monthly late penalty for life. iStockphoto By Kimberly Lankford, Contributing Editor From Kiplinger's Personal Finance, January 2017 Do I need to buy Medicare Part D if I am not on a lot of prescription medications? --D.S., Wilmington, N.C.SEE ALSO: 11 Common Medicare Mistakes No, but if you ever do need Part D coverage, you’ll be subject to late penalties that will increase your costs as long as you have the coverage. If you go more than 63 days after the end of the period you first become eligible (a seven-month window that runs three months before to three months after the month you turn 65) without having creditable drug coverage, such as an employer or retiree plan, you’ll have to pay a late-enrollment penalty every month for life. The penalty is 1% of the national base Part D premium (set each year by the Centers for Medicare and Medicaid Services) for each month you delayed. The base premium was $34.10 in 2016, so someone who delayed signing up for three years would pay an extra $12.28 penalty every month. SEE ALSO: How to Save With a Medicare Prescription Drug Plan Got a question? Ask Kim at email@example.com.