Original Medicare: The Complete Guide to Washington

Original Medicare is the foundation of federal healthcare for Americans aged 65 and older, as well as for certain younger individuals with qualifying disabilities. Administered directly by the federal government through the Centers for Medicare & Medicaid Services (CMS), it is the traditional fee-for-service health insurance program that has existed since 1965.

If you are approaching Medicare eligibility in Washington, understanding Original Medicare is your mandatory first step. Even if you ultimately plan to enroll in private coverage—such as a Medicare Advantage plan from UnitedHealthcare, Kaiser Permanente, or Regence BlueShield—your eligibility, baseline costs, and fundamental rights all stem from how Original Medicare operates.

Original Medicare is split into two distinct halves: Part A, which functions as hospital insurance, and Part B, which functions as medical insurance. Together, they cover a vast array of healthcare services, but they do not cover everything, and they are not entirely free.

This comprehensive guide breaks down exactly what Original Medicare covers, what it costs, the critical deadlines you must meet, and how Washington residents can successfully navigate the system to protect both their health and their finances.

Medicare Part A: Hospital Insurance Explained

Medicare Part A is designed to cover the care you receive when you are formally admitted into a medical facility. It is your financial safety net for major medical events, surgeries, and serious illnesses that require round-the-clock professional medical supervision.

What Part A Covers

Part A coverage is generally restricted to inpatient care. Specifically, it covers:

• Inpatient Hospital Care: Room and board, general nursing, drugs administered as part of your inpatient treatment, and hospital services and supplies during your stay.
• Skilled Nursing Facility (SNF) Care: Care provided in an SNF is covered only if it follows a qualifying three-day inpatient hospital stay and is for a related medical condition. This covers skilled nursing, rehabilitation services, and meals.
• Hospice Care: For individuals with a terminal illness (a life expectancy of six months or less), Part A covers pain relief, symptom management, and support services.
• Home Health Care: Under specific, restricted conditions, Part A covers part-time or intermittent skilled nursing care, physical therapy, speech-language pathology, and occupational therapy for individuals who are homebound.

The Cost of Part A: Premiums and Benefit Periods

For the vast majority of Washington residents, Medicare Part A is “premium-free.” If you or your spouse worked and paid Medicare taxes for at least 40 calendar quarters (equivalent to 10 years), you do not have to pay a monthly premium for Part A coverage. If you have fewer than 40 quarters of work history, you can still buy into Part A by paying a monthly premium, the exact amount of which is prorated based on the number of quarters you did work.

However, “premium-free” does not mean care is free. Part A operates on a Benefit Period system for its deductibles and coinsurance, which is distinctly different from the annual deductibles you may be used to with employer-sponsored health insurance.

A benefit period begins the day you are admitted to a hospital or skilled nursing facility as an inpatient. The benefit period ends when you have not received any inpatient hospital care (or skilled care in a SNF) for 60 days in a row.

When you use Part A services, you are responsible for:

1. The Part A Deductible: This is a set dollar amount you must pay out-of-pocket before Medicare begins to pay for your inpatient care. Because this deductible applies per benefit period, not per calendar year, you could potentially have to pay it multiple times in a single year if you are hospitalized, discharged for more than 60 days, and then hospitalized again.
2. Inpatient Hospital Coinsurance: For days 1 through 60 of a hospital stay in a benefit period, you pay a $0 coinsurance. For days 61 through 90, you pay a daily coinsurance amount.
3. Lifetime Reserve Days: For days 91 and beyond, you tap into your “lifetime reserve days” (you have a maximum of 60 over your entire life), which require an even higher daily coinsurance payment. Once these are exhausted, you pay all costs.

Understanding the benefit period is critical because a prolonged or repeated hospital stay under Original Medicare alone can result in tens of thousands of dollars in out-of-pocket costs.

Medicare Part B: Medical Insurance Explained

While Part A covers where you stay during major medical events, Medicare Part B covers the everyday medical care that keeps you out of the hospital in the first place. Part B is the workhorse of your healthcare coverage, applying to outpatient services, doctor visits, and preventative care.

What Part B Covers

Part B coverage is expansive, applying to two main categories of services: medically necessary services (services or supplies needed to diagnose or treat a medical condition) and preventive services (care aimed at preventing illnesses like the flu or detecting them at an early stage).

• Doctor and Provider Visits: Routine visits to your primary care physician and consultations with specialists.
• Outpatient Care: Surgeries, procedures, and observation stays conducted in a hospital or clinic setting where you are not formally admitted as an inpatient.
• Preventative Services: Flu shots, pneumococcal shots, cardiovascular screenings, cancer screenings (like mammograms and colonoscopies), and an annual “Wellness” visit.
• Durable Medical Equipment (DME): Blood sugar monitors, test strips, CPAP machines, wheelchairs, walkers, and oxygen equipment prescribed by a doctor for use in your home.
• Mental Health Services: Outpatient mental health care, including therapy, counseling, and psychiatric evaluations.
• Clinical Laboratory Services: Blood tests, urinalysis, and tissue pathology.
• Ambulance Services: Emergency transportation to the nearest medical facility equipped to provide the necessary care.

The Cost of Part B: Premiums, Deductibles, and Coinsurance

Unlike Part A, everyone pays a premium for Medicare Part B.

The Standard Premium and IRMAA The federal government sets a standard Part B premium annually. This standard premium applies to the majority of Medicare beneficiaries. However, if your modified adjusted gross income (MAGI) from two years prior exceeds a certain threshold, you will be subject to the Income-Related Monthly Adjustment Amount (IRMAA). IRMAA is an additional surcharge added to your standard Part B (and Part D) premium. The Social Security Administration automatically determines if you owe IRMAA based on your IRS tax filings.

The Part B Deductible Part B carries an annual deductible. This is a single, relatively low deductible that resets on January 1st every year. You must pay 100% of your medical bills out-of-pocket up to this deductible amount before Part B begins to share the costs.

The 20% Coinsurance (The Infinite Liability) After your annual deductible is met, you typically pay 20% of the Medicare-approved amount for most doctor services, outpatient therapy, and durable medical equipment. Medicare pays the remaining 80%.

This 20% coinsurance is the most dangerous aspect of Original Medicare’s cost structure. There is no yearly limit (no out-of-pocket maximum) on what you can pay in Part B coinsurance. If you require expensive outpatient procedures, high-cost injectable medications administered in a doctor’s office, or extensive ongoing physical therapy, your 20% share can quickly drain your retirement savings.

The “Medicare-Approved Amount” and Provider Assignment

When you see a doctor under Original Medicare, the costs are dictated by whether the doctor accepts “Medicare Assignment.”

• Participating Providers: These doctors accept assignment, meaning they agree to accept the Medicare-approved amount as full payment for covered services. You pay exactly your 20% coinsurance, and nothing more.
• Non-Participating Providers: These doctors accept Medicare but do not accept assignment. They can charge up to 15% more than the Medicare-approved amount (this extra charge is called a “limiting charge”). You are responsible for your 20% coinsurance plus the additional 15% limiting charge.
• Opt-Out Providers: These doctors have formally opted out of the Medicare program entirely. Medicare will pay nothing for their services, and you are responsible for 100% of the bill out-of-pocket, governed by a private contract you sign with the doctor.

Eligibility and Enrollment in Washington

Timing is everything when it comes to Medicare. Unlike private health insurance, which generally allows you to jump on a plan during an annual Open Enrollment period with no questions asked, Original Medicare enforces permanent financial penalties if you miss your initial window to enroll.

The Initial Enrollment Period (IEP)

Your Initial Enrollment Period is a seven-month window tied directly to your 65th birthday. It includes:

• The three full calendar months before the month you turn 65.
• The month you turn 65.
• The three full calendar months after the month you turn 65.

If you are already receiving Social Security retirement benefits when you turn 65, you will typically be enrolled in Parts A and B automatically, and your Medicare card will arrive in the mail a few months before your birthday. If you are not yet drawing Social Security, you must proactively apply for Medicare through the Social Security Administration (either online, by phone, or at a local Washington SSA office).

Delaying Medicare: The Employer Coverage Exception

If you or your spouse are still actively working at age 65 and you are covered by a qualifying employer-sponsored group health plan (from a company with 20 or more employees), you can generally safely delay enrolling in Part B without penalty.

Because Part A is usually free, many working individuals go ahead and enroll in Part A at 65 to serve as secondary hospital coverage, while declining Part B to save on the monthly premium. However, if your employer health plan is an HSA-eligible High Deductible Health Plan, enrolling in any part of Medicare will instantly disqualify you from continuing to make tax-advantaged contributions to your HSA.

Special Enrollment Periods (SEP)

When you finally retire or lose that employer coverage, you are granted a Special Enrollment Period. You have a strict eight-month window starting the month after your employment ends or your employer coverage ends (whichever happens first) to enroll in Part B without facing a penalty.

Crucial Warning: COBRA continuation coverage and retiree health plans do not count as current employer coverage. If you take COBRA and delay Part B, you will incur a late enrollment penalty when you eventually sign up.

Late Enrollment Penalties

If you miss your IEP and do not qualify for an SEP, the consequences are severe:

• Part B Penalty: Your monthly premium increases by 10% for each full 12-month period you were eligible for Part B but did not enroll. This penalty is not a one-time fee; you pay it every month for the rest of your life.
• Part A Penalty: If you are required to buy Part A and delay enrollment, your monthly premium may increase by 10%. You must pay this higher premium for twice the number of years you delayed enrollment.

If you missed your window, you must wait for the General Enrollment Period (GEP), which runs from January 1st to March 31st each year. Your coverage will then begin the month following your enrollment.

What Original Medicare Does Not Cover

One of the biggest misconceptions new beneficiaries have is assuming that Original Medicare is comprehensive, all-inclusive health insurance. By law, Original Medicare is prohibited from paying for several major categories of healthcare that seniors heavily rely on.

If you have only Original Medicare in Washington, you will pay 100% out-of-pocket for:

• Routine Dental Care: Exams, cleanings, fillings, extractions, and dentures are strictly excluded. Medicare only covers dental care if it is inextricably linked to a covered medical procedure (e.g., extracting a tooth to perform jaw surgery).
• Routine Vision Care: Eye exams for prescribing glasses or contact lenses are not covered. (Medicare does cover medically necessary eye care, such as cataract surgery and glaucoma screenings).
• Routine Hearing Care: Hearing exams, hearing aids, and exams for fitting hearing aids are excluded.
• Outpatient Prescription Drugs: Aside from a few very specific medications administered directly by a physician, medications you pick up at a pharmacy (like statins, blood pressure pills, or insulin) are not covered by Parts A and B.
• Long-Term Care: Medicare is designed for acute medical events, not chronic custodial care. It will not pay for long-term care in a nursing home, assisted living facility, or for personal care attendants to help with daily living activities (bathing, dressing, eating).
• Alternative Care: Massage therapy, acupuncture (except under extremely narrow circumstances for chronic lower back pain), and most chiropractic services (except manual manipulation of the spine to correct a subluxation).

Filling the Gaps: Your Next Steps in Washington

Because Original Medicare has unlimited 20% financial exposure and glaring coverage gaps, leaving it unprotected is a massive financial risk. Washington residents generally choose one of two distinct pathways to complete their health insurance portfolio.

Option 1: Original Medicare + Medigap + Part D

This is the “traditional” route. You keep Original Medicare as your primary insurance, retaining your ability to see any doctor in the U.S. who accepts Medicare, without referrals.

To protect against the deductibles and the 20% coinsurance, you purchase a private Medicare Supplement Insurance (Medigap) policy. Medigap plans are standardized by letter (Plan G, Plan N, etc.). A comprehensive Medigap plan will pay nearly all of your approved out-of-pocket costs, turning a catastrophic medical bill into a fully covered event.

Because Original Medicare does not cover prescriptions, you must also purchase a standalone Medicare Part D prescription drug plan to avoid a separate Part D late enrollment penalty and to ensure your medications are covered.

Option 2: Medicare Advantage (Part C)

The alternative route is to replace the federal administration of your benefits with a private Medicare Advantage plan. When you join a Medicare Advantage plan, you still have Medicare, and you must continue paying your Part B premium. However, the private insurance company (such as Humana, Aetna Medicare, or Devoted Health) takes over the responsibility of providing your Part A and Part B benefits.

For 2026, Washington residents have access to 124 different Medicare Advantage plans across the state. These plans function similarly to traditional private insurance:

• Networks: You generally must use a defined network of local doctors and hospitals (HMO or PPO).
• Out-of-Pocket Maximums: By law, all Medicare Advantage plans must include a hard cap on your annual medical spending, offering the financial protection Original Medicare lacks.
• Bundled Coverage: Most MA plans include Part D prescription drug coverage built-in (known as MA-PD plans, such as the AARP Medicare Advantage from UHC (PPO) or the AARP Medicare Advantage Essentials from UHC (HMO-POS)).
• Extra Benefits: MA plans often fund the extras Original Medicare ignores, offering allowances for dental, vision, hearing, and over-the-counter health items.

How to Make Your Medicare Decision

Choosing how to configure your Medicare coverage in Washington requires assessing your health, your finances, and how you prefer to consume healthcare.

1. Assess Your Travel and Provider Preferences: If you travel frequently outside of Washington, live in multiple states throughout the year, or have complex medical conditions requiring out-of-state specialists, the network-free nature of Original Medicare paired with a Medigap policy is often the safest choice.
2. Evaluate Your Budget: Medigap plans require a substantial, separate monthly premium, but offer highly predictable out-of-pocket costs at the point of service. Medicare Advantage plans often advertise $0 monthly premiums, but you will pay copayments as you use services (pay-as-you-go) and are restricted by network boundaries.
3. Review Your Prescriptions: Gather a list of every medication you take, including dosages. Because Original Medicare does not cover pharmacy drugs, this list will dictate which standalone Part D plan or which bundled Medicare Advantage plan provides the best formulary coverage for your specific needs.
4. Understand Your Rights: If you choose a Medicare Advantage plan when you first turn 65, you have specific trial rights that allow you to switch back to Original Medicare and buy a Medigap policy without medical underwriting. However, if you try to switch to a Medigap plan later in life, insurance companies in Washington generally have the right to look at your medical history and can deny you coverage or charge you more based on pre-existing conditions.

Original Medicare is a powerful, historic program that guarantees seniors access to the national healthcare system. By understanding its structure, its costs, and its limitations, you can make informed decisions to secure comprehensive, financially protective healthcare for your retirement years.

Frequently Asked Questions