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Original Medicare Enrollment Part 4 - How to enroll in Medicare if you are under 65 and have a disability
If you become eligible for Medicare because of a disability and have been receiving Social Security Disability Insurance (SSDI) or railroad disability annuity checks for 24 months, you should automatically be enrolled in both Medicare Parts A and B at the start of your 25th month.
You should not have to contact anyone. You should receive a package in the mail three months before your coverage starts with your new Medicare card. There will also be a letter explaining how Medicare works and that you were automatically enrolled in both Parts A and B. If you get Social Security retirement benefits, your package and card will come from the Social Security Administration (SSA). If you get railroad disability annuity checks, your package and card will come from the Railroad Retirement Board.
The letter also explains that your monthly Part B premium will be automatically deducted from your Social Security check or railroad disability annuity check beginning the month your coverage begins.
Typically, you should not turn down Part B unless you have insurance based on your or your spouse’s current work (job-based insurance). If you do not have job-based insurance and you turn down Part B, you may incur a premium penalty if you need to sign up for Medicare coverage in the future. Also, if your job-based insurance will pay secondary after you become eligible for Medicare, you should consider enrolling in Medicare in order to have primary coverage and pay less for your care.
If you were not automatically enrolled or have other enrollment questions, contact your local Social Security office or Railroad Retirement Board field office.