If your family is anything like mine, everyone has a certain specialist or role in keeping the household running.

Since I wash dishes faster than anyone, I’m the family dishwashing expert. I’m also the point man for paying medical bills. My wife and I have separate health coverage, so I have to make sure our providers have the up-to-date information they need to accurately bill our respective insurance plans.

If you have Medicare as well as other insurance, always be sure to tell your doctor, hospital, and pharmacy. This is important because it determines whether your medical bills are paid correctly and on time.

When there’s more than one insurance payer, certain rules determine which one pays first. These rules are called “coordination of benefits.”

The “primary payer” pays what it owes on your bills first – and then sends the balance to the “secondary payer” to pay. In some cases, there may also be a third payer.

Medicare is the primary payer for beneficiaries who aren’t covered by other types of health insurance.

The primary payer pays up to the limits of its coverage. The secondary payer only pays if there are costs the primary insurer didn’t cover.

But keep in mind that the secondary payer (which may be Medicare) may not pay all of the uncovered costs.

If you currently have employer insurance and it’s the secondary payer, you may need to enroll in Medicare Part B before your job-based coverage will pay. (Most people who sign up for Part B for the first time this year will pay a monthly premium of $134.)

Here’s who pays first in various situations when you have Medicare and some of type of insurance as well: if you have a retiree insurance (coverage from a former job), Medicare pays first. If you’re 65 or older, have a group coverage based on your or your spouse’s current employment, and the employer has 20 or more workers, your group plan pays first. (If the company has fewer than 20 employees, Medicare pays first.)

Your group plan also pays first when you’re under 65 and disabled, have group coverage based on your or a family member’s current employment, and the employer has 100 or more employees. (Medicare pays first if the company has fewer than 100 employees.)

If you have Medicare because of end-stage renal disease (permanent kidney failure), your group plan pays first for the first 0 months after you become eligible for Medicare. Medicare pays first after this 30-month period.

Medicare may pay second if you’re in an accident or have a Workers’ Compensation case in which other insurance covers your injury or you’re suing another entity for medical expenses.

In such situation you or your lawyer should tell Medicare as soon as possible. The following types of insurance usually pay first for services related to each type: No fault insurance (including automobile insurance); liability (including automobile and self-insurance); black lung benefits; Workers’ Compensation.

Medicare and TRICARE (the healthcare program for U.S. arms service members, retirees, and their families) never pay first for services that are covered by Medicare. They only pay after Medicare, employer plans, and/or Medicare Supplement Insurance (Medigap) has paid.

For more information, read the booklet “Medicare and Other Health Benefits: Your Guide to Who Pays First.” You can find it online at: http://www.medicare.gov/Pubs/pdf/02179.pdf

You may also call toll-free at 1-800-MEDICARE (1-800-633-4227) and ask for a copy to be mailed to you. TTY users should call 1-877-486-2048.

If you have questions about who pays first, or if your coverage changes, call the Benefits Coordination & Recovery Center toll free at 1-855-798-2627. TTY users should call 1-855-797-2627. You can also contact your employer or union benefits administrator. You may need to give your Medicare number to your other insurers so your bills are paid correctly and on time. You can always get answers to your Medicare question by calling 1-800-MEDICARE (1-800-633-4227).