How to Choose Original Medicare A & B

Navigating the landscape of healthcare in your golden years can feel like deciphering a complex code. For many, the first and most fundamental step is understanding Original Medicare, specifically Parts A and B. This isn’t just a government program; it’s a foundational safety net, a bedrock of health coverage for millions of Americans aged 65 and over, and certain younger individuals with disabilities. Choosing Original Medicare isn’t a passive decision; it’s an active step that shapes your access to care, your out-of-pocket costs, and the flexibility you’ll experience in managing your health. This comprehensive guide will dissect Original Medicare Parts A and B, providing you with the knowledge and actionable insights to make an informed choice that aligns with your individual healthcare needs and financial comfort.

The Foundation: What Exactly is Original Medicare?

Original Medicare is the traditional, government-run health insurance program. It’s a fee-for-service plan, meaning you typically pay a portion of the costs for covered services as you receive them. It’s composed of two primary parts:

• Part A (Hospital Insurance): Primarily covers inpatient hospital stays, care in a skilled nursing facility, hospice care, and some home health services. Think of it as your inpatient safety net.

• Part B (Medical Insurance): Covers medically necessary services and preventive services. This is your outpatient coverage, including doctor visits, outpatient care, medical supplies, and preventive services.

Unlike private insurance plans that often bundle services, Original Medicare keeps these two components distinct. Understanding what each part covers and what it doesn’t cover is crucial for making smart decisions about your overall healthcare strategy.

Eligibility for Original Medicare A & B: Are You Qualified?

Before diving into the intricacies of coverage and costs, let’s establish who is eligible for Original Medicare. The eligibility criteria are generally straightforward, but there are nuances.

Age-Based Eligibility (65 and Older)

Most individuals become eligible for Medicare when they turn 65. To qualify for premium-free Part A (which we’ll discuss in detail later), you or your spouse must have worked and paid Medicare taxes for at least 10 years (40 quarters).

• Example: Sarah turned 65. She worked for 35 years as a teacher and always paid Medicare taxes. She automatically qualifies for premium-free Part A. Her husband, John, also turned 65 and only worked for 5 years, but because Sarah worked for 35 years, John also qualifies for premium-free Part A based on her work record.

If you don’t meet the 10-year work requirement, you may still be able to get Part A, but you’ll have to pay a monthly premium.

• Example: Maria is 65 and moved to the U.S. later in life. She’s only worked and paid Medicare taxes for 7 years. She can still get Part A, but she’ll pay a prorated monthly premium.

For Part B, almost everyone who is eligible for Part A is also eligible for Part B by paying a monthly premium. You don’t need a work history to qualify for Part B.

Disability-Based Eligibility (Under 65)

Medicare isn’t just for seniors. Younger individuals can qualify for Medicare if they have certain disabilities or conditions:

• Social Security Disability Insurance (SSDI) Benefits: If you’ve been receiving SSDI benefits for 24 months, you’re generally eligible for Medicare Parts A and B, regardless of your age.
  • Example: David, 48, was diagnosed with a debilitating illness and began receiving SSDI benefits. After 24 months, he automatically received his Medicare card.
• End-Stage Renal Disease (ESRD): Individuals of any age with permanent kidney failure requiring dialysis or a kidney transplant are eligible for Medicare.
  • Example: Emily, 32, started dialysis due to kidney failure. After a waiting period, she became eligible for Medicare.
• Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease: There’s no waiting period for individuals with ALS once they become eligible for Social Security disability benefits.
  • Example: Robert, 55, was diagnosed with ALS. As soon as his Social Security disability benefits were approved, he became eligible for Medicare immediately.

Decoding Medicare Part A: Your Hospital Insurance

Medicare Part A is the “hospital insurance” component. It’s designed to cover the significant costs associated with inpatient care.

What Part A Covers:

• Inpatient Hospital Care: This is the core of Part A. It covers stays in acute care hospitals, long-term care hospitals, inpatient rehabilitation facilities, and inpatient psychiatric facilities. Coverage includes a semi-private room, meals, general nursing, medications administered during your stay, and other hospital services and supplies.
  • Example: You suddenly experience severe chest pain and are admitted to the hospital for a heart attack. Part A will cover your stay, including your room, meals, nursing care, and the medications administered by the hospital staff during your inpatient treatment.
• Skilled Nursing Facility (SNF) Care: After a qualifying inpatient hospital stay, Part A can cover skilled nursing care in a facility. This is not custodial care (like help with daily activities) but rather skilled services like physical therapy, occupational therapy, speech therapy, and skilled nursing care.
  • Example: After a hip replacement surgery, your doctor recommends a short stay in a skilled nursing facility for intensive physical therapy. Part A would cover this if you meet the specific criteria for a qualifying hospital stay beforehand.
• Hospice Care: If you have a terminal illness and choose hospice care, Part A covers services like pain management, symptom control, and support for you and your family. There are minimal out-of-pocket costs for medications and respite care.
  • Example: A loved one with a terminal illness opts for hospice care at home. Part A would cover the services of the hospice team, including nurses, social workers, and aides, as well as medications to manage discomfort.
• Some Home Health Care: Part A can cover certain home health services if you are homebound and need skilled nursing care or therapy on an intermittent basis.
  • Example: After a stroke, you need intermittent skilled nursing visits and physical therapy at home. Part A would cover these services if you meet the homebound criteria.

What Part A Doesn’t Cover:

It’s equally important to understand what Part A doesn’t cover, as these are areas where you might incur significant out-of-pocket costs or need supplemental coverage.

• Private-duty nursing.

• A private room (unless medically necessary).

• Personal care items (like razors or slippers).

• Long-term custodial care (like assisted living or nursing home care for non-medical needs).

• Doctor fees during a hospital stay (these fall under Part B).

Unpacking Medicare Part B: Your Medical Insurance

Medicare Part B is your “medical insurance.” It’s the part that covers your day-to-day healthcare needs, including doctor visits and outpatient services.

What Part B Covers:

• Medically Necessary Services: These are services or supplies that are needed to diagnose or treat your medical condition and that meet accepted standards of medical practice.
  • Doctor’s Services: This includes visits to your primary care physician and specialists, whether in their office, a hospital outpatient setting, or your home.
    • Example: You have a persistent cough and see your family doctor. Part B covers this office visit. If your doctor refers you to a pulmonologist, Part B also covers that specialist visit.
  • Outpatient Care: Services received at a hospital outpatient department, such as observation stays, emergency room visits (that don’t result in inpatient admission), and outpatient surgery.
    • Example: You go to the emergency room for a minor injury and are treated and released without being admitted. Part B covers these services.
  • Durable Medical Equipment (DME): Medically necessary equipment like wheelchairs, walkers, oxygen equipment, hospital beds, and nebulizers.
    • Example: Your doctor prescribes a wheelchair after surgery to aid your recovery at home. Part B covers a portion of the cost for this durable medical equipment.
  • Lab Tests and X-rays: Diagnostic tests to help your doctor understand your condition.
    • Example: Your doctor orders a blood test to check your cholesterol levels and an X-ray of your knee due to pain. Part B covers these diagnostic services.
  • Mental Health Services: Outpatient mental health care, including visits with psychiatrists, psychologists, and clinical social workers, as well as partial hospitalization programs.
    • Example: You seek therapy for anxiety. Part B covers sessions with your therapist.
  • Ambulance Services: Covered when medically necessary and transportation by other means could endanger your health.
    • Example: You experience a medical emergency and need to be transported by ambulance to the nearest hospital. Part B covers the ambulance service.
• Preventive Services: Crucial for maintaining health and detecting issues early. Many preventive services are covered 100% by Part B if you receive them from a provider who accepts assignment (meaning they agree to accept the Medicare-approved amount as full payment).
  • Annual Wellness Visit: A yearly visit focused on developing or updating a personalized prevention plan.
    • Example: You schedule your annual wellness visit to discuss your health and preventive care strategies with your doctor. This visit is fully covered.
  • Certain Screenings: Screenings for conditions like cancer (colorectal, breast, cervical, prostate), diabetes, cardiovascular disease, and glaucoma.
    • Example: You get a mammogram as part of your routine breast cancer screening. Part B covers this at no cost to you.
  • Flu Shots and Other Vaccinations: Essential for preventing common illnesses.
    • Example: You get your annual flu shot at your doctor’s office. Part B covers the cost entirely.

What Part B Doesn’t Cover:

Part B doesn’t cover everything, and these exclusions are significant.

• Routine Vision Care: Eye exams for prescription glasses or contacts. (However, Part B does cover medical eye conditions like glaucoma or cataracts).

• Routine Dental Care: Most dental procedures, cleanings, and dentures.

• Routine Hearing Care: Hearing exams for hearing aids, and the hearing aids themselves.

• Long-Term Custodial Care: Non-medical care like help with bathing, dressing, and eating, whether at home or in a nursing home.

• Cosmetic Surgery.

• Acupuncture.

• Most Prescription Drugs: This is a major one. Original Medicare (Parts A and B) generally does not cover outpatient prescription drugs. For prescription drug coverage, you would need to enroll in a separate Medicare Part D plan.

• Healthcare while traveling outside the U.S. (with a few very limited exceptions).

Understanding the Costs of Original Medicare A & B

While Original Medicare provides essential coverage, it’s not entirely free. You’ll have various out-of-pocket costs, which are important to budget for.

Medicare Part A Costs (2025 Figures for Illustration):

• Premium:
  • Most people pay $0: If you or your spouse worked and paid Medicare taxes for at least 10 years (40 quarters), your Part A premium is free. This applies to about 99% of beneficiaries.

  • Premium for those with less work history: If you worked between 7.5 and 10 years (30-39 quarters), the monthly premium for 2025 is $285. If you worked fewer than 7.5 years (under 30 quarters), the monthly premium for 2025 is $518.

• Deductible: For 2025, the Part A deductible for an inpatient hospital stay is $1,676 per benefit period. This is crucial: it’s not an annual deductible. A “benefit period” begins the day you’re admitted to a hospital or skilled nursing facility and ends when you haven’t received inpatient hospital or skilled nursing care for 60 consecutive days. You could potentially pay this deductible multiple times in a single year if you have separate benefit periods.

  • Example: You are hospitalized in March, pay the $1,676 deductible, and are discharged in April. You are readmitted to the hospital in August for a different issue, and this marks the start of a new benefit period. You would pay the $1,676 deductible again.
• Coinsurance for Hospital Stays: After the deductible is met, Part A covers the full cost for the first 60 days of an inpatient hospital stay within a benefit period.
  • Days 61-90: You pay a daily coinsurance of $419 (2025 figure).

  • Days 91-150: These are “lifetime reserve days.” You have 60 lifetime reserve days that you can use once over your lifetime. For these days, you pay a daily coinsurance of $838 (2025 figure). Once these 60 days are used, you pay all costs for hospital stays beyond day 150.

  • Example: You’re in the hospital for 75 days. You pay the $1,676 deductible, then $419/day for days 61-75.

• Coinsurance for Skilled Nursing Facility (SNF) Stays:

  • Days 1-20: $0 coinsurance.

  • Days 21-100: You pay a daily coinsurance of $209.50 (2025 figure).

  • After Day 100: You pay all costs.

  • Example: You have a qualifying SNF stay for 30 days. You pay $0 for the first 20 days, and then $209.50 per day for days 21-30.

Medicare Part B Costs (2025 Figures for Illustration):

• Premium: Most people pay a standard monthly premium for Part B. For 2025, this standard premium is $185 per month. This premium is typically deducted from your Social Security benefits.

  • Income-Related Monthly Adjustment Amount (IRMAA): If your modified adjusted gross income (MAGI) from two years prior (e.g., your 2023 income for your 2025 premium) exceeds certain thresholds, you’ll pay a higher Part B premium. These are called Income-Related Monthly Adjustment Amounts (IRMAA). The thresholds are adjusted annually.
    • Example: In 2023, you were a high-income earner. Even if your income drops in 2025, your Part B premium for 2025 will be based on your 2023 income, resulting in a higher IRMAA payment.
• Deductible: For 2025, the Part B annual deductible is $257. You must pay this amount out of pocket before Medicare Part B starts to pay for your covered services.

• Coinsurance: After you meet your Part B deductible, Medicare generally pays 80% of the Medicare-approved amount for most covered services, and you are responsible for the remaining 20% coinsurance. There is no out-of-pocket maximum with Original Medicare. This means if you have extensive medical needs, your 20% coinsurance could add up significantly.

  • Example: After meeting your $257 Part B deductible, you have a doctor’s visit for which the Medicare-approved amount is $100. Medicare pays $80, and you pay $20 (20% coinsurance). If you have several appointments or medical tests throughout the year, these 20% coinsurance payments can accumulate quickly.

When and How to Enroll in Original Medicare

Enrolling in Medicare is time-sensitive. Missing your enrollment periods can lead to lifelong late enrollment penalties.

Initial Enrollment Period (IEP)

This is your first opportunity to enroll in Medicare. It’s a seven-month window centered around your 65th birthday:

• Three months before the month you turn 65.

• The month you turn 65.

• Three months after the month you turn 65.

• Example: If your birthday is in July, your IEP begins April 1st and ends October 31st.

Crucial Advice: If you enroll during the first three months of your IEP, your coverage generally starts the first day of your birthday month. If you enroll in your birthday month or the three months after, your coverage start date will be delayed.

Automatic Enrollment

You might be automatically enrolled in Medicare Parts A and B if you’re already receiving Social Security or Railroad Retirement Board (RRB) benefits at least four months before you turn 65. Your Medicare card will typically be mailed to you about three months before your 65th birthday.

• Example: If you started receiving Social Security retirement benefits at age 62, you’ll automatically be enrolled in Medicare Parts A and B when you turn 65.

If you’re automatically enrolled and don’t want Part B (perhaps because you’re still working and have employer coverage), you’ll need to follow the instructions on your Medicare card to decline Part B.

Special Enrollment Period (SEP)

If you’re still working past age 65 and have health coverage through your employer (or your spouse’s employer), you might be able to delay enrolling in Part B without penalty. Once your employer coverage ends (or you stop working), you’ll qualify for a Special Enrollment Period (SEP) to sign up for Part B.

• This SEP typically lasts for eight months after your employer coverage ends or you stop working (whichever happens first).

• Example: You turn 65 but continue working and are covered by your employer’s health plan. You decide to retire at 67. You’ll have an 8-month SEP to enroll in Part B without a late enrollment penalty.

Important Note for Part A: Even if you’re still working, it’s generally advisable to enroll in Part A when you’re first eligible if it’s premium-free, as it can act as secondary coverage for hospital stays.

General Enrollment Period (GEP)

If you miss your Initial Enrollment Period and you don’t qualify for a Special Enrollment Period, you can enroll during the General Enrollment Period, which runs from January 1st to March 31st each year. However, if you enroll during this period, your coverage won’t start until July 1st, and you may face a late enrollment penalty for Part B.

Late Enrollment Penalties

• Part B Late Enrollment Penalty: If you don’t sign up for Part B when you’re first eligible and you don’t qualify for a Special Enrollment Period, your monthly premium may increase by 10% for each full 12-month period you could have had Part B but didn’t sign up. This penalty is permanent.
  • Example: You were eligible for Part B for two years but didn’t sign up. Your monthly premium will be 20% higher for as long as you have Part B.
• Part A Late Enrollment Penalty: This is less common because most people qualify for premium-free Part A. However, if you have to pay a Part A premium and you don’t sign up when you’re first eligible, your monthly premium may increase by 10% and you’ll have to pay it for twice the number of years you delayed enrollment.

How to Enroll:

• Online: The easiest way for most people is to apply online through the Social Security Administration’s website.

• By Phone: You can call the Social Security Administration.

• In Person: Visit your local Social Security office.

What Original Medicare Doesn’t Do: The Gaps in Coverage

This is where the term “Original Medicare” often becomes a starting point, not a destination. While it provides critical coverage, it has significant gaps:

• No Out-of-Pocket Maximum: As mentioned, there’s no cap on how much you could pay in a year for the 20% coinsurance for Part B services. A major illness or chronic condition could lead to substantial medical bills.

• No Prescription Drug Coverage (Part D): Original Medicare generally doesn’t cover outpatient prescription drugs. You’ll need to enroll in a separate Medicare Part D Prescription Drug Plan (PDP) if you want this coverage.

• No Routine Dental, Vision, or Hearing Coverage: These are common and often costly services that Original Medicare does not cover.

• Limited Coverage Outside the U.S.: Original Medicare generally doesn’t cover healthcare while you’re traveling outside the United States, except in a few very specific and limited situations.

Addressing the Gaps: Medigap and Part D

Because of the out-of-pocket costs and coverage gaps in Original Medicare, many beneficiaries choose to purchase additional coverage.

Medicare Supplement Insurance (Medigap) Plans:

Medigap policies are private health insurance plans that help pay some of the healthcare costs that Original Medicare doesn’t cover, like deductibles, copayments, and coinsurance.

• Standardized Plans: Medigap policies are standardized, meaning each plan letter (e.g., Plan G, Plan N) offers the same basic benefits, regardless of the insurance company selling it. This makes comparing plans easier.

• Coverage Example: A common Medigap plan, like Plan G, covers your Part A deductible, Part A coinsurance, Part B coinsurance (the 20%), and the Part B deductible. With such a plan, your out-of-pocket costs for Medicare-approved services would be minimal after paying your Part B deductible and the Medigap premium.

• Freedom of Choice: With Original Medicare and a Medigap plan, you can see any doctor, specialist, or hospital nationwide that accepts Medicare. There are no networks.

• Enrollment Period: The best time to buy a Medigap policy is during your Medigap Open Enrollment Period. This 6-month period begins the first month you are 65 or older and enrolled in Medicare Part B. During this time, insurance companies cannot use medical underwriting to deny you a policy or charge you more due to health conditions. If you miss this window, you might not be able to buy a Medigap policy, or you might pay more.

• Important: You cannot have a Medigap policy and a Medicare Advantage Plan simultaneously.

Medicare Part D (Prescription Drug Plans):

Since Original Medicare doesn’t cover most outpatient prescription drugs, a stand-alone Part D plan is essential for many.

• Private Plans: Part D plans are offered by private insurance companies approved by Medicare.

• Formularies: Each plan has a list of covered drugs called a “formulary.” This list can vary significantly between plans, so it’s vital to check if your medications are covered and at what cost.

• Premiums, Deductibles, Coinsurance/Copayments: Part D plans have their own monthly premiums, annual deductibles, and varying copayments or coinsurance for different tiers of drugs.

• “Donut Hole” (Coverage Gap): Historically, there was a coverage gap or “donut hole” where you paid a higher percentage for your drugs after reaching a certain spending limit. While this gap has largely been closed, understanding the different phases of Part D coverage is still important.

• Late Enrollment Penalty: If you go for a continuous period of 63 days or more without creditable prescription drug coverage (which means coverage as good as Medicare’s), you may incur a permanent late enrollment penalty for Part D when you do eventually sign up.

Original Medicare vs. Medicare Advantage: A Crucial Comparison

Choosing Original Medicare is often compared to choosing a Medicare Advantage (Part C) plan. This is a fundamental decision that will significantly impact your healthcare experience.

Original Medicare (Parts A & B):

• Administered by the federal government.

• Nationwide Acceptance: You can go to any doctor, specialist, or hospital in the U.S. that accepts Medicare. No networks mean more flexibility.

• No Referrals: Generally, you don’t need a referral to see a specialist.

• No Out-of-Pocket Limit: This is a major con. Your 20% Part B coinsurance could lead to very high costs.

• Gaps in Coverage: Does not include routine dental, vision, hearing, or most prescription drug coverage.

• Supplemental Plans (Medigap & Part D): To mitigate out-of-pocket costs and add prescription drug coverage, you typically combine Original Medicare with a Medigap plan and a Part D plan. This creates a comprehensive package.

Medicare Advantage (Part C):

• Administered by private insurance companies approved by Medicare. These plans bundle your Part A, Part B, and often Part D (prescription drug) benefits into one plan.

• Network Restrictions: Most Medicare Advantage plans operate with provider networks (HMOs, PPOs). You may be limited to doctors and hospitals within the plan’s network, or pay more for out-of-network care.

• Referrals: Some plans, especially HMOs, require referrals to see specialists.

• Out-of-Pocket Maximum: All Medicare Advantage plans have an annual out-of-pocket maximum. Once you reach this limit, the plan pays 100% of your covered Part A and B services for the rest of the year. This provides financial protection.

• Extra Benefits: Many Medicare Advantage plans offer additional benefits not covered by Original Medicare, such as routine dental, vision, hearing, fitness programs, and even some over-the-counter allowances.

• Lower Premiums (Often): Some Medicare Advantage plans have a $0 additional monthly premium beyond your Part B premium. However, you’ll still pay copayments and coinsurance for services.

• No Medigap: You cannot purchase a Medigap policy if you are enrolled in a Medicare Advantage plan.

Deciding Between the Two:

The choice between Original Medicare (plus Medigap and Part D) and Medicare Advantage boils down to a few key considerations:

1. Flexibility vs. Cost Structure:
   • Original Medicare + Medigap + Part D: Offers maximum flexibility in choosing providers and generally lower out-of-pocket costs per service (due to Medigap covering the 20% coinsurance). However, you pay three separate premiums (Part B, Medigap, Part D).

   • Medicare Advantage: Offers a potentially lower monthly premium (or $0 additional premium) but trades that for network restrictions and usually higher copayments/coinsurance per service until you hit the out-of-pocket maximum. You get bundled benefits.

2. Health Needs and Predictability:

   • If you anticipate needing frequent or specialized care, or if you prefer the peace of mind of virtually no out-of-pocket costs for covered services, Original Medicare with a comprehensive Medigap plan might be a better fit.

   • If you’re generally healthy, prefer a simpler, bundled plan, value extra benefits, and are comfortable with network limitations and copayments, a Medicare Advantage plan could be attractive.

3. Travel Habits:

   • If you travel frequently within the U.S. or live in different states for parts of the year, Original Medicare’s nationwide acceptance is a significant advantage. Medicare Advantage plans are typically tied to specific service areas.

Strategic Considerations for Choosing Original Medicare A & B

Choosing Original Medicare isn’t just about signing up; it’s about understanding how it integrates with your broader healthcare and financial plan.

Considering Future Health Needs:

While you might be healthy now, think about potential future health challenges. A chronic illness or unexpected medical event could quickly accumulate costs under Original Medicare if you don’t have supplemental coverage. This is why pairing it with a Medigap plan is so common.

Evaluating Your Budget:

Factor in the combined premiums for Part B, a Medigap plan, and a Part D plan. Compare this total monthly cost against the potential out-of-pocket expenses you might face with Original Medicare alone or a Medicare Advantage plan.

Provider Preferences:

Do you have specific doctors or specialists you want to continue seeing? Ensure they accept Medicare. With Original Medicare, most providers who accept Medicare are available to you.

Prescription Drug Needs:

Carefully review your current medications and how they’d be covered by various Part D plans. The costs for specific drugs can vary wildly between plans, even for the same medication. Use Medicare’s Plan Finder tool to compare.

Don’t Duplicate Coverage:

It’s critical to understand that you cannot have a Medigap policy and a Medicare Advantage Plan at the same time. If you choose Original Medicare, you can add Medigap and Part D. If you choose Medicare Advantage, those are your primary benefits, and Medigap cannot be used.

Get Personalized Advice (But Do Your Own Research Too):

While this guide provides comprehensive information, your specific situation is unique. Organizations like your State Health Insurance Assistance Program (SHIP) can offer free, unbiased counseling. However, always verify information and compare options yourself.

Conclusion: Your Empowered Medicare Choice

Choosing Original Medicare Parts A and B is a pivotal decision in your healthcare journey. It offers a solid foundation of hospital and medical insurance, backed by the federal government, providing unparalleled freedom in choosing your doctors and hospitals nationwide. However, this flexibility comes with the caveat of potentially significant out-of-pocket costs and the necessity of adding a Medigap policy and a separate Part D prescription drug plan to achieve more comprehensive coverage.

By meticulously understanding the eligibility requirements, the specific coverages of Part A and Part B, the associated costs, and the critical enrollment periods, you equip yourself to make an informed decision. Don’t view Original Medicare as a “set it and forget it” choice; rather, see it as the robust starting point for building a healthcare plan that truly serves your needs, protects your finances, and ensures you have access to the care you deserve as you navigate life’s later stages. Your health is your most valuable asset, and making a deliberate, well-researched choice about your Medicare coverage is an investment in your well-being.