Medicare Part A and Part B: Your Guide to Original Medicare Coverage, Differences, and Enrollment

Navigating Medicare Part A and Part B can feel overwhelming, especially if you’re approaching age 65 or helping a loved one make Medicare decisions. Understanding what Original Medicare covers, the key differences between Part A and Part B, and how enrollment works is crucial for choosing the right health insurance in Castle Pines, Colorado. This comprehensive guide answers your biggest questions — in plain, compassionate language — so you can make insurance decisions with clarity and confidence.

What Is the Difference Between Medicare Part A and Part B?

Medicare was established by the federal government to provide health insurance coverage for adults age 65 and older, as well as some younger individuals with disabilities or End-Stage Renal Disease. The core of the program, known as Original Medicare, consists of Part A (hospital insurance) and Part B (medical insurance). Understanding what each part covers is essential to avoid coverage gaps and surprise costs.

Medicare Part A: Often called hospital insurance, Part A helps pay for inpatient care in hospitals, skilled nursing facilities (not long-term care or custodial nursing home stays), some home health care, and hospice services.
Medicare Part B: Known as medical insurance, Part B covers outpatient care, doctor visits, many preventive services, lab tests, durable medical equipment, and certain home health services.

Most people are eligible for both Part A and Part B when they first sign up for Medicare, typically around their 65th birthday. You can learn more about the overall framework on our in-depth page: Medicare Parts A, B, C & D Explained at Simply Insurance.

a friendly insurance agent helping a senior couple review Medicare paperwork in a bright Colorado office

Who Is Eligible for Medicare Part A and Part B in Colorado?

You qualify for Original Medicare if you meet these criteria as set by Medicare (United States):

You are age 65 or older and either a U.S. citizen or a legal resident who has lived in the U.S. for at least five consecutive years.
If under 65, you must have a qualifying disability (after receiving Social Security Disability Insurance for 24 months) or be diagnosed with End-Stage Renal Disease or ALS.
You or your spouse worked and paid Medicare taxes for at least 10 years (40 quarters), which usually waives your Part A premium.

Residents of Castle Pines and neighboring Colorado communities should also note that if you receive Social Security or Railroad Retirement Board benefits at least four months before you turn 65, you will be automatically enrolled in both Part A and Part B.

What Does Medicare Part A Cover?

Part A is hospital insurance. It covers:

Inpatient hospital care (after you are formally admitted by a doctor), including semi-private rooms, meals, nursing care, and some hospital services and supplies.
Skilled nursing facility care after a qualifying three-night inpatient hospital stay, but not long-term custodial or nursing home care.
Hospice care for patients with a terminal illness and life expectancy of six months or less.
Home health care (certain conditions apply) when skilled care is needed after an inpatient stay.

However, Part A does not cover:

Routine doctor visits (see Part B)
Private-duty nursing
Long-term custodial care in a nursing home
Most prescription drugs

You’ll pay a deductible for each benefit period ($1,632 in 2024, per Centers for Medicare & Medicaid Services). After that, Part A generally covers 100% of your inpatient hospital costs for the first 60 days, then you pay daily coinsurance for longer stays.

What Does Medicare Part B Cover?

Medicare Part B is medical insurance. This part covers:

Doctor/physician services (including specialists in Castle Pines and throughout Colorado)
Outpatient care and surgery
Preventive services, like vaccinations, cancer screenings, and annual wellness visits
Lab tests and X-rays
Durable medical equipment (like wheelchairs, walkers, oxygen)
Some home health services (when you meet qualifying criteria)
Mental health services, including outpatient therapy

Part B does not cover:

Most dental, vision, and hearing care
Routine foot care
Prescription drug coverage (that is covered under Medicare Part D)

You must pay a monthly premium for Part B. In 2024, the standard Part B premium is $174.70 per month, according to Medicare.gov, but this amount may be higher based on your income. You’ll also need to pay a small annual deductible ($240 in 2024), after which you usually pay 20% coinsurance for covered services.

When and How Should You Enroll in Medicare Part A and Part B?

Enrollment is a critical step. Missing deadlines can lead to late enrollment penalties and gaps in your Medicare coverage. Here’s what you need to know:

The Initial Enrollment Period for Medicare Part A and Part B starts three months before the month you turn 65, includes your birthday month, and extends three months after — for a total of 7 months.
If you are already drawing Social Security or Railroad Retirement benefits, enrollment is automatic.
If not, you must actively sign up for Medicare at your local Social Security office, online, or by calling the Social Security Administration.
If you’re working past 65 and have employer health coverage, you may be able to delay Part B without penalty — but review the rules carefully and get professional guidance to avoid unintended costs.

Medicare Initial Enrollment Steps for Coloradans

If you miss signing up during your Initial Enrollment Period, you may have to wait for the General Enrollment Period (January 1–March 31) and could pay penalties. Calculate your potential Medicare Part B late enrollment penalty or Part D penalty with our free online tools.

How Much Does Medicare Part A and Part B Cost?

Original Medicare costs can be confusing, but knowing what to expect helps you budget — and spot the value of supplemental coverage. Here’s what Coloradans should know:

Part A premium: Most people do not pay a monthly premium for Part A if they or a spouse paid Medicare payroll taxes for at least 10 years (40 quarters). If you do have to pay, the monthly premium can be up to $505 (2024 rate).
Part B premium: In 2024, the base premium is $174.70 monthly, but it can be higher if your annual income is above $103,000 (individual) or $206,000 (married, filing jointly).
Deductibles and coinsurance: You’ll pay a hospital deductible for each benefit period (currently $1,632 for Part A), and 20% of most covered outpatient services under Part B after your deductible is met.

These costs do not include prescription drug coverage, which requires a Medicare Part D plan, or extra protection from high out-of-pocket medical expenses, which requires a Medigap (Medicare supplement) plan.

Which Health Services Are Not Covered by Original Medicare?

It’s important to understand the coverage gaps in Medicare Part A and Part B, so you can plan for additional insurance, such as a Medicare Advantage plan or Medigap. Services generally not covered by Original Medicare include:

Prescription drug coverage (requires a Part D drug plan)
Dental care and dentures
Routine eye exams and most vision care
Hearing aids and exams
Long-term custodial nursing home care
Most care outside the United States

This is why working with a trusted, local agent — like those at Simply Insurance — can help you compare all your options and build a complete health insurance solution for your needs.

a local Colorado couple discussing Medicare options with a knowledgeable insurance advisor, surrounded by informational brochures

What Are Supplemental Medicare Options Beyond Part A and Part B?

Once you understand what’s covered by Parts A and B, explore ways to enhance your Medicare coverage. The main options include:

Medigap (Medicare Supplement Insurance): Private plans that help pay Part A and Part B deductibles, coinsurance, and certain out-of-pocket costs. Medigap does not include drug coverage — you’ll need a Part D drug plan for that.
Medicare Part D: Stand-alone plans for prescription drug coverage, required if you want help with ongoing prescription drug costs.
Medicare Advantage (Part C): Plans offered by Medicare-approved private companies that bundle all Original Medicare services and often include prescription drug, vision, dental, and other benefits.

Understanding the difference between Original Medicare (Parts A and B), a Medicare Advantage plan (Part C), and standalone drug plans (Part D) is vital for each retiree or caregiver. Get more details on each in our helpful resource: Medicare Parts A, B, C & D Explained.

Why Choose a Local Colorado Agent for Medicare Part A and Part B Enrollment?

Medicare isn’t a one-size-fits-all solution. Your health history, prescription needs, retirement timeline, and even which part of Colorado you live in can affect the best coverage choices. Working with a trusted, local agent means you benefit from experience in Colorado’s Medicare landscape, access to multiple plan options, and ongoing support for enrollment, annual reviews, and claims questions.

Personalized guidance simplifies complex insurance decisions.
One-on-one support ensures no detail is missed in your enrollment.
Help comparing Part A, Part B, Medigap, Medicare Advantage, and prescription drug plans ensures you get coverage tailored to your life.
Assistance with Social Security and late enrollment questions helps prevent costly mistakes.

Simply Insurance was founded in 2016 and is committed to industry best practices outlined by the Centers for Medicare & Medicaid Services (CMS).

How to Take the Next Step with Medicare Part A and Part B in Castle Pines

Choosing and enrolling in Medicare Part A and Part B is a major milestone — but you don’t have to face it alone. If you’re confused by the parts of Medicare, unsure about costs, or want help comparing your options, the Medicare experts at Simply Insurance are here for you. We’ll walk you through every step, from confirming eligibility to explaining premiums and benefits, so you can make confident decisions and protect your health and finances.

Contact Simply Insurance today for a local, no-pressure Medicare consultation focused on your needs. Together, we’ll ensure your Medicare coverage fits your life — and your peace of mind.

This article is for informational purposes only and does not constitute financial advice. Consult a qualified professional for your specific situation.