Medicare Basics in 2025
Medicare is a federal health insurance program for people 65+, certain younger individuals with disabilities, or those with End-Stage Renal Disease (ESRD). In 2025, it offers multiple parts and options—Parts A, B, C, D, and Medigap—each with specific coverage, costs, and enrollment rules. This guide explains it all, including the Income-Related Monthly Adjustment Amount (IRMAA), charts, examples, and what you need to do.
Who’s Eligible?
You qualify for Medicare if you:
- Are 65 or older and a U.S. citizen or legal resident (5+ years).
- Are under 65 with a qualifying disability (after 24 months of SSDI).
- Have ESRD or ALS (immediate eligibility).
Example: John, 66, worked 15 years—eligible for premium-free Part A. Lisa, 45, on SSDI for 2 years—also eligible.
Medicare Parts Explained
Medicare has four main parts, plus supplemental options:
| Part | Coverage | Cost (2025) |
|---|---|---|
| Part A | Hospital stays, skilled nursing, hospice | Free (10+ work years); $458/month otherwise |
| Part B | Doctor visits, outpatient, preventive care | $174.70/month (standard); +IRMAA for high earners |
| Part C (Advantage) | A+B, often D, extras (vision, dental) | Varies by plan |
| Part D | Prescription drugs | $0-$100+/month (plan-dependent) |
| Medigap | Supplements A+B (e.g., copays) | $50-$300+/month |
Tip: Part A is free if you or your spouse paid Medicare taxes for 40 quarters (10 years).
Enrollment Periods
Timing matters—miss deadlines, and you’ll face penalties:
- Initial Enrollment Period (IEP): 7 months around your 65th birthday (3 before, month of, 3 after).
- General Enrollment: Jan 1–Mar 31 yearly (coverage starts July 1; Part B penalty: 10% per year missed).
- Special Enrollment Period (SEP): 8 months after employer coverage ends (no penalty).
- Open Enrollment: Oct 15–Dec 7 yearly (change Part C/D plans).
Example: Mary turns 65 in June 2025. Her IEP runs March–September 2025—enroll by June to avoid gaps.
How to Enroll
Automatic if on Social Security at 65; otherwise:
- Online: SSA.gov (3 months before 65).
- Phone: 1-800-772-1213 (7 AM–7 PM, Mon–Fri).
- In-Person: Local SSA office (Find one).
Watch this video for a deeper dive into Medicare basics!
Understanding IRMAA (Income-Related Monthly Adjustment Amount)
High earners pay extra for Parts B and D via IRMAA, based on your Modified Adjusted Gross Income (MAGI) from 2 years prior (2023 for 2025). Here’s the 2025 IRMAA chart:
| Income (Single) | Income (Married Filing Jointly) | Part B Extra | Part D Extra |
|---|---|---|---|
| ≤ $103,000 | ≤ $206,000 | $0 | $0 |
| $103,001–$129,000 | $206,001–$258,000 | $69.90 | $12.90 |
| $129,001–$161,000 | $258,001–$322,000 | $174.70 | $33.30 |
| $161,001–$193,000 | $322,001–$386,000 | $279.50 | $53.80 |
| $193,001–$500,000 | $386,001–$750,000 | $384.30 | $74.20 |
| > $500,000 | > $750,000 | $419.00 | $81.00 |
What to Do with IRMAA:
- Check Your Notice: SSA mails IRMAA notices in late 2024—review your 2023 tax return.
- Appeal if Wrong: File Form SSA-44 (download) if income dropped (e.g., retirement, divorce).
- Plan Ahead: Reduce MAGI (e.g., Roth conversions) 2 years before Medicare age.
Example: Tom’s 2023 MAGI is $150,000 (single). In 2025, he pays $174.70 + $174.70 = $349.40/month for Part B, plus $33.30 for Part D.
Medicare Advantage (Part C)
Private plans combining A, B, often D, with extras (vision, dental). Enrollment: IEP or Open Enrollment.
Original Medicare vs. Medicare Advantage
Chart: Relative strengths (higher = better).
Tip: Compare plans at Medicare.gov.
Part D Drug Coverage
Prescription drug plans—costs vary:
- Premium: $0-$100+/month.
- Deductible: Up to $590 in 2025.
- Copays: Vary by drug tier.
Example: Sue pays $35/month for Part D, $10 copay for generics—total $45/month.
Medigap (Supplemental Insurance)
Fills gaps in Original Medicare (e.g., copays, deductibles). Plans A-N available:
| Plan | Covers | Avg. Cost (2025) |
|---|---|---|
| Plan G | Part B excess, most out-of-pocket | $150-$200/month |
| Plan F | All gaps (pre-2020 enrollees) | $200-$300/month |
| Plan N | Lower premiums, some copays | $100-$150/month |
Tip: Enroll during Medigap Open Enrollment (6 months from Part B start)—no health questions.
2025 Costs and Updates
- Part A Deductible: $1,632/stay.
- Part B Deductible: $240/year.
- Out-of-Pocket Max (Part C): $8,850 (varies by plan).
- Update: Telehealth expanded in Advantage plans.
Extra Help Program
For low-income individuals—cuts Part D costs:
- Income Limit: ~$22,590 (single), $30,660 (married).
- Apply: SSA.gov.
Top Medicare Providers in 2025
Original Medicare (Parts A & B) covers essentials, but private insurance providers like Humana, Aetna, and UnitedHealthcare offer Medicare Advantage (Part C) and Part D plans to enhance your coverage. These plans often include extras like prescription drugs, dental, vision, and hearing—plus lower out-of-pocket costs. Explore these trusted providers to find the best plan for your needs.
Humana
Humana offers affordable Medicare Advantage and Part D plans with wellness programs and nationwide coverage.
Visit Humana
Aetna
Aetna provides comprehensive Medicare plans focusing on preventive care and broad networks.
Visit Aetna
UnitedHealthcare
The largest Medicare Advantage provider, offering flexible plans with extensive doctor networks.
Visit UnitedHealthcareFrequently Asked Questions (FAQs)
Do I need Part B if I’m working?
No—if employer coverage is primary (20+ employees), delay Part B penalty-free.
What’s IRMAA appeal process?
File SSA-44 with proof of life event (e.g., job loss)—takes 60 days.
Advantage or Original?
Advantage for extras; Original for flexibility—depends on your needs.
Get Started
Enroll or explore options at Medicare.gov.
Need Help?
Call 1-800-MEDICARE (1-800-633-4227) or visit an SSA office (locate).