Medicare is a federal health insurance program designed to provide coverage for individuals aged 65 and older, as well as younger individuals with certain disabilities or conditions like End-Stage Renal Disease (ESRD) or ALS. This guide explains Medicare basics including its parts, enrollment process, and coverage options, to help you make informed decisions about your healthcare.
Overview: Medicare basics
What Are the Parts of Medicare?
Medicare is divided into four main parts, each covering specific healthcare needs. Here’s a breakdown:
| Medicare Part | What It Covers | Costs |
|---|---|---|
| Part A (Hospital) | Inpatient hospital stays, skilled nursing facility care, hospice, and home health | Typically free if you or your spouse paid Medicare taxes for 10+ years; otherwise, premiums apply |
| Part B (Medical) | Outpatient care, doctor visits, preventive services, and durable medical equipment | Monthly premiums (standard for 2025 is $174.70) and an annual deductible |
| Part C (Advantage) | An alternative to Original Medicare; includes Parts A & B and often Part D | Varies by plan; may include additional benefits like vision or dental |
| Part D (Drugs) | Prescription drug coverage | Monthly premiums and copayments based on the specific plan |
Who Is Eligible for Medicare?
You are eligible for Medicare if:
- You are 65 years or older.
- You are under 65 but have a qualifying disability and have received Social Security Disability Insurance (SSDI) for at least 24 months.
- You have ESRD or ALS.
How to Enroll in Medicare
Automatic Enrollment
If you’ve been receiving Social Security benefits for at least four months before turning 65, you’ll automatically be enrolled in Medicare Part A and Part B. You can choose to delay Part B if you have other qualifying health coverage[2][8].
Signing Up Manually
If you’re not receiving Social Security benefits yet, you’ll need to enroll manually during your Initial Enrollment Period (IEP). This seven-month window starts three months before your 65th birthday month and ends three months after it[2][8].
Special Enrollment Periods (SEPs)
If you’re still working and covered by an employer’s group health plan when you turn 65, you may qualify for an SEP to enroll in Medicare without penalties after your employment ends[1][7].
When Does Coverage Start?
The timing of your enrollment determines when your coverage begins:
- If you enroll during the first three months of your IEP, coverage starts on the first day of your birthday month.
- If you enroll during your birthday month or the three months after, coverage starts the following month[3][8].
What Are My Coverage Options?
You can choose between two main paths for Medicare:
- Original Medicare (Parts A & B):
- Offers flexibility in choosing doctors and hospitals that accept Medicare.
- Doesn’t include prescription drug coverage; you’ll need a standalone Part D plan if required.
- Option to add Medigap (supplemental insurance) for help with out-of-pocket costs.
- Medicare Advantage Plans (Part C):
- Combines Parts A & B and often includes Part D.
- May offer additional benefits like vision, dental, hearing aids, or wellness programs.
- Requires using a network of providers in most cases[1][3].
Key Deadlines to Remember
- Initial Enrollment Period (IEP): Starts three months before your 65th birthday month and ends three months after it.
- Annual Open Enrollment Period: October 15 – December 7 each year; allows changes to Advantage or Part D plans for the next year[3][9].
- Medicare Advantage Open Enrollment: January 1 – March 31 each year; allows switching between Advantage plans or returning to Original Medicare[5].
Medicare provides essential healthcare coverage tailored to meet the needs of seniors and individuals with disabilities. By understanding medicare basics with its parts and enrollment process, you can confidently navigate your options and select the best plan for your healthcare needs.
Sources
[1] Medicare Managed Care Eligibility and Enrollment – CMS https://www.cms.gov/medicare/enrollment-renewal/managed-care-eligibility-enrollment
[2] How Do I Sign Up for Medicare? – NerdWallet https://www.nerdwallet.com/article/insurance/medicare/how-do-i-sign-up-for-medicare
[3] Joining a plan | Medicare https://www.medicare.gov/basics/get-started-with-medicare/get-more-coverage/joining-a-plan
[4] Become a Medicare Provider or Supplier – CMS https://www.cms.gov/medicare/enrollment-renewal/providers-suppliers
[5] [PDF] 2025 Medicare Resource Guide for Patients – Janssen CarePath https://asset.janssencarepath.com/document/medicare-resource-guide.pdf
[6] Medicare Enrollment Guide for Institutional Providers – CMS https://www.cms.gov/medicare/provider-enrollment-and-certification/enroll-as-an-institutional-provider
[7] [PDF] Medicare – SSA https://www.ssa.gov/pubs/EN-05-10043.pdf
[8] How and when to apply for Medicare – USAGov https://www.usa.gov/medicare
[9] Medicare Annual Enrollment Period Guide 2025 | HealthPartners Blog https://www.healthpartners.com/blog/medicare-open-annual-enrollment-period-aep/
