Once you’ve chosen a Part D plan, it’s easy to sign up. But first make sure that it’s the plan you want and that you haven’t been talked into it by a salesperson who doesn’t have your best interests at heart.

How can I enroll?

1. On the phone by calling Medicare at 1-800-633-4227. If you’re hard of hearing and use TTY, call 1-877-486-2048 toll free.

2. Online at www.medicare.gov. Click on “Health and Drug Plans” on the left-hand menu of the home page and then on the “Enrol Nowl” link that will appear alongside.

3. By contacting the plan of your choice at its website or at the phone number provided in its brochure or on Medicare’s website.

When can I enroll?

If you’re signing up with a Part D plan for the first time, you may do so in one of three different enrollment periods, depending on your circumstances:

Initial Enrollment Period (IEP): If you’re not yet in Medicare and have no other drug coverage that’s “creditable” (considered as good as Medicare’s), you can join a drug plan at any time during your seven-month initial Medicare enrollment period. This lasts from three months before to three months after the month you turn 65 (or, if you’re younger with disabilities, the month you receive your 25th Social Security disability payment). You can also use this IEP if you turned 65 while living abroad or in prison. It lasts from three months before to three months after the month of your return or release.

Special Enrollment Period (SEP): You’re entitled to an SEP in certain circumstances—for example, if you lose creditable drug coverage (such as from an employer or union), or you turned 65 before moving abroad or going to prison and now want Part D coverage on your return or release. You do not have to request an SEP in these circumstances, but can just go ahead and sign up with a plan. This kind of SEP lasts 63 days and you must be receiving Part D coverage before it expires to avoid a late penalty.

Annual Open Enrollment Period (OEP): If you miss your deadline for joining Part D during an IEP or an SEP, then you cannot enroll in a drug plan until the next OEP. This enrollment period (which until the end of 2010 ran from November 15 to December 31) now runs from October 15 to December 7 each year. You also have to wait for an OEP if you deliberately drop creditable drug coverage that you already have (for example, from an employer or union). The OEP also serves as an annual opportunity for anybody already enrolled in Part D to switch from one plan to another.

What questions will I be asked?

Whether you enroll online, on the phone or on a written form, you must answer certain standard questions for your enrollment to be considered complete. These include:

Your primary address: This is the place you consider your normal home—the one used on your tax form and driver’s license—even if you live part of the year in another state. You cannot be enrolled in two Part D plans in different places, and your primary home must be within the service area of the plan you choose. If you don’t have a fixed address, the Part D plan you want may accept the address of a shelter or clinic, a PO box number or wherever you receive mail.

Whether you have (or had) other drug coverage: Medicare requires this information to ensure that your other benefits can be coordinated with Part D, so that the pharmacist knows what to charge you and who to bill for the balance. Also it allows the plan to confirm that you know the consequences of joining Part D, in case doing so would affect your other coverage adversely. And it shows whether you’ve been without creditable drug coverage for long enough to incur a Part D late penalty.

How you want to pay your premiums: You must choose one of three options: having the plan bill you directly; having the premiums deducted automatically from your Social Security check; or arranging for the premiums to be sent to the plan automatically by electronic funds transfer from your bank account. You are asked to indicate your preference on the enrollment form and generally must stick with your choice for the rest of the year.