This Mother's Day is the best of times to help your mom save an average of $3,900 a year on her prescription drug costs. Here's how.

If your mother is covered by Medicare and has limited income and resources, she may be eligible for extra help available through Social Security to pay part of her monthly premiums, annual deductibles and prescription copayments. The extra help is worth an average of $3,900 per year.

To figure out whether she is eligible, Social Security needs to know her income and the value of her savings, investments and real estate, other than the home she lives in.

To qualify for the extra help, she must be receiving Medicare and her income must be not more than $16,245 for an individual or $21,855 for a married couple living together. Even if her annual income is higher, she still may be able to get some help with monthly premiums, annual deductibles and prescription co-payments.

Some examples where income may be higher include if she or her husband supports other family members who live with them, have earnings from work, or live in Alaska or Hawaii.

She must also have resources limited to $12,510 for an individual or $25,010 for a married couple living together. Resources include such things as bank accounts, stocks and bonds. Neither her house nor her car are counted as resources.

Social Security has an online application that you can help complete at www.socialsecurity.gov/ prescriptionhelp.

To apply by phone or have an application mailed, go to the nearest Social Security office or call Social Security at (800) 772-1213 (TTY 800-325-0778) and ask for the Application for Help with Medicare Prescription Drug Plan Costs/ SSA-1020.

For more information, visit www.medicare.gov.