Medicare Program Overview for Plan Workers

Q: What is the difference between Original Medicare and Medicare Advantage?

Original Medicare (Parts A and B) is administered by CMS with no network restrictions and no out-of-pocket maximum. Medicare Advantage (Part C) is delivered by private insurers with provider networks, referrals, prior authorisation requirements, and an annual out-of-pocket maximum. MA plans often include extra benefits and Part D. Members in MA still pay their Part B premium.

Q: What are the main Medicare enrollment periods a plan worker needs to know?

IEP: 7 months around age 65 (3 before, birthday month, 3 after). AEP: October 15 to December 7 (plan switching). MA OEP: January 1 to March 31 (switch MA plans or return to Original Medicare). SEPs: qualifying events like moving, losing other coverage, or qualifying for Extra Help.

Q: What is the Part B late enrollment penalty and when does it apply?

A permanent 10% penalty on the Part B premium for each full 12-month period without Part B coverage when no valid SEP applies. Example: 2 years without Part B = 20% higher premium permanently.

Q: What is the Low-Income Subsidy (Extra Help) and how does it affect Part D costs?

Extra Help reduces Part D premiums, deductibles, and copayments for members with limited income. Full Extra Help means little or no Part D premium and reduced copayments. Always check LIS status before quoting drug costs, LIS members have significantly different cost-sharing than standard members.

Q: What changed in Medicare Part D in 2025?

The out-of-pocket cap was set at $2,000 annually under the Inflation Reduction Act. The Medicare Prescription Payment Plan (M3P) allows members to pay drug costs in monthly installments. The maximum Part D deductible is $590 in 2025.

Q: Does a member in Medicare Advantage still have to pay the Part B premium?

Yes. MA members still pay the Part B premium (approximately $185/month in 2025, more for higher earners via IRMAA) in addition to any plan premium. Some MA plans offer a Part B premium reduction (giveback benefit). Never tell an MA member they have no Part B premium obligation.

WORKER SAFETY: Medicare Programme Knowledge

Medicare Program Overview: What Every Plan
Worker Needs to Know

If you work for a Medicare Advantage plan, a pharmacy benefit manager, a member services call centre, or a healthcare compliance team, your job depends on knowing how Medicare works. Getting the basics wrong costs members money, causes incorrect enrollments, and generates compliance violations that can lead to CMS enforcement action. This guide covers the Medicare programme, Parts A, B, C, and D, in plain language, so every person on your team can do their job correctly.

67M+

Americans on Medicare in 2025

Over 67 million Americans were enrolled in Medicare as of mid-2025, making it the largest public health insurance programme in the United States. Medicare covers roughly one in five Americans 65 or older and eligible disabled individuals under 65. Every error a plan worker makes affects a real person depending on this programme for their health care.

Medicare Policy Overview: State of Medicare, August 2025

4 Parts

Parts A, B, C, and D

Medicare is divided into four parts. Part A covers hospital care. Part B covers medical and outpatient care. Part C (Medicare Advantage) is the private plan alternative that bundles A and B and usually D. Part D covers prescription drugs. Each part has its own eligibility rules, enrollment periods, costs, and coverage limits, and you need to understand all four.

Medicare.gov: Get Started with Medicare

7 months

Initial Enrollment Period Window

The Initial Enrollment Period (IEP) is a 7-month window: the 3 months before the person turns 65, their birthday month, and the 3 months after. Missing this window without a qualifying Special Enrollment Period leads to late enrollment penalties on Part B (10% per year missed) and Part D. Knowing enrollment periods is basic job knowledge for anyone handling Medicare enrollment.

Medicare.gov: When Does Coverage Start

Hazard Overview: What Goes Wrong When Workers Get Medicare Wrong

The “hazard” for a plan worker is not a physical injury. It is giving a Medicare member wrong information, processing an enrollment incorrectly, or misidentifying which part of Medicare covers a service. These errors harm real people. They can also generate compliance violations, CMS audit findings, grievances, and appeals that cost your organisation time, money, and its regulatory standing.

The most common knowledge gaps that cause problems in day-to-day plan operations fall into four categories.

Part Confusion

Telling a member that their hospital stay is covered under Part D (it is Part A), or that their prescription is covered under Part B (it depends on where it is administered). Mixing up the parts causes wrong coverage explanations and incorrect benefit determinations.

Enrollment Period Errors

Processing an enrollment outside a valid period, or failing to recognise a qualifying Special Enrollment Period. An invalid enrollment creates a CMS compliance problem. Failing to honour a valid SEP denies a member their legal right to enrol.

Cost-Sharing Misinformation

Telling a member the wrong deductible, copay, or coinsurance for a service. This leads members to make healthcare decisions based on incorrect cost expectations, and generates complaints, grievances, and potential regulatory exposure when they receive unexpected bills.

Original Medicare vs. Medicare Advantage Confusion

Not knowing the difference between Original Medicare (Parts A and B administered by CMS) and Medicare Advantage (Part C, administered by private plans). The two have different network rules, cost-sharing structures, prior authorisation requirements, and appeal processes. Applying the wrong set of rules to a member inquiry causes serious downstream errors.

Signs of Danger: When to Stop and Check Before You Answer

If you are on a call or handling a case and any of the following is true, stop before you give an answer. Look up the correct information or escalate to a supervisor. A wrong answer given confidently is worse than saying “let me check that for you.”

You are not sure which Medicare part covers the service the member is asking about. Do not guess. Look it up or transfer to someone who knows.

A member is asking about enrolling in or leaving the plan, and you are not certain which enrollment period is currently open or whether their situation qualifies for a Special Enrollment Period.

A member is asking about their cost-sharing for a specific service and you are giving them a number from memory rather than from their current plan’s benefit summary.

A member is comparing Original Medicare with Medicare Advantage and you are not confident you understand the key differences in network rules, referrals, and prior authorisation.

A member mentions a late enrollment penalty and you are not sure how it is calculated or whether it applies in their situation.

Medicare Program Overview: Parts A, B, C, D, and Enrollment Periods

Part A: Hospital Insurance

Part A covers inpatient hospital stays, care in a skilled nursing facility after a qualifying hospital stay, hospice care, and some home health services. Most people get Part A premium-free if they or their spouse paid Medicare taxes for at least 10 years (40 quarters) of work. Part A has a deductible per benefit period (not per calendar year), plus coinsurance for longer hospital stays. For plan workers: Part A covers the inpatient side. When a member asks about a hospital admission, a skilled nursing facility stay, or hospice, that is a Part A question. Source: Medicare.gov: Parts of Medicare

Part B: Medical Insurance

Part B covers doctor visits, outpatient care, preventive services (screenings, flu shots, annual wellness visits), mental health services, ambulance services, durable medical equipment, and some home health services. Part B requires a monthly premium, the standard amount in 2025 is approximately $185 per month, though higher earners pay more through the IRMAA adjustment. Part B has an annual deductible, after which Medicare pays 80% and the member pays 20% with no out-of-pocket maximum in Original Medicare. For plan workers: Part B covers the outpatient side. Doctor appointments, lab tests, X-rays, outpatient surgery, and preventive care are all Part B. Source: Triage Cancer: 2025 Medicare Quick Guide

Part C: Medicare Advantage

Medicare Advantage is the private plan alternative to Original Medicare. A member enrolled in Part C gets their Part A and Part B benefits through a private insurance company approved by CMS, not directly from the federal government. Most MA plans also include Part D drug coverage. MA plans often offer extra benefits not in Original Medicare, such as dental, vision, hearing, and fitness programmes. However, MA plans typically use networks of doctors and hospitals, may require referrals for specialists, and may require prior authorisation for certain services. Members must still pay their Part B premium even when enrolled in a Medicare Advantage plan. For plan workers: if you work for a Medicare Advantage organisation, this is the product your members have. Understanding how it differs from Original Medicare is essential for correctly answering questions about networks, referrals, and prior authorisations. Source: Medicare.gov: Medicare Advantage Plans

Part D: Prescription Drug Coverage

Part D covers prescription drugs through plans offered by private insurers approved by CMS. Part D is optional but carries a late enrollment penalty if a member goes without creditable drug coverage for more than 63 continuous days. In 2025, the maximum Part D deductible is $590. Each Part D plan has a formulary, a list of covered drugs, and drugs are divided into tiers with different cost-sharing. Members pay more for higher-tier (brand-name or specialty) drugs. In 2025, the out-of-pocket cap for Part D was set at $2,000 annually under the Inflation Reduction Act changes. For plan workers at MA-PD organisations: Part D is built into your plan. You need to know how the formulary tiers work, what the transition policy is for new enrollees, and when prior authorisation is required for specific drugs. Source: Triage Cancer: 2025 Medicare Quick Guide

IEP

Enrollment Periods: When Members Can Join or Change Plans

Four periods matter most for plan workers. The Initial Enrollment Period (IEP) is the 7-month window around a person’s 65th birthday, 3 months before, the birth month, and 3 months after. The Annual Election Period (AEP) runs October 15 to December 7 each year, this is when members can switch plans, and changes take effect January 1. The Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 to March 31, members already in a Medicare Advantage plan can switch to a different MA plan or return to Original Medicare during this window. Special Enrollment Periods (SEPs) allow changes outside normal windows when a qualifying event occurs (moving, losing other coverage, qualifying for Extra Help). Missing an enrollment window without a valid SEP leads to late penalties. For plan workers: you must know which window is open before processing any enrollment or disenrollment request. Source: PHLP: Medicare 2025 Enrollment Periods

LIS

Low-Income Subsidy (Extra Help) and Dual Eligibility

Some Medicare members qualify for extra financial assistance. The Low-Income Subsidy (LIS), also called Extra Help, reduces Part D premiums, deductibles, and copayments for members with limited income and resources. Dual-eligible members qualify for both Medicare and Medicaid, they have special rules and protections, including access to D-SNP (Dual-Eligible Special Needs Plans). For plan workers: LIS status and dual-eligibility status affect how a member’s cost-sharing is calculated and which plans they can access. Always verify a member’s LIS or dual-eligibility status before discussing their costs. Getting this wrong leads to incorrect cost information and potential compliance violations. Source: Medicare.gov: Extra Help with Part D Costs

Do / Do Not: Medicare Knowledge Rules for Plan Workers

DO

✓

Look up the member’s current plan benefits before quoting any cost-sharing figure

✓

Verify which enrollment period is currently open before processing any enrollment or disenrollment

✓

Check the member’s LIS and dual-eligibility status before discussing their drug costs

✓

Say “let me check that for you” or transfer to a supervisor when you are unsure, it is always the right call

✓

Document every member interaction with the correct issue type, not free-text description

DO NOT

✗

Do not give a member cost-sharing information from memory, always look it up from their current benefit summary

✗

Do not process an enrollment request without confirming the member is in a valid enrollment period

✗

Do not confuse Original Medicare rules with Medicare Advantage rules when answering member questions

✗

Do not assume a drug is covered without checking the plan’s formulary for that specific member

✗

Do not tell a member they have no appeal rights, every member has the right to appeal a coverage denial

Emergency Response: What to Do When You Give Wrong Information

You realise mid-call or immediately after that you gave wrong information

Correct it immediately. If you are still on the call, say: “I need to correct something I just told you.” Give the right information. Document in the call record that a correction was made and what the correction was. Do not leave incorrect information standing on a call record without noting it was corrected. If the call has ended, escalate to your supervisor so the member can be contacted with the correction before they take any action based on the wrong information.

A member was incorrectly enrolled or disenrolled based on wrong information

Escalate to your supervisor immediately. Do not attempt to fix an incorrect enrollment or disenrollment on your own. Incorrect enrollments may require a CMS-approved correction process. Prompt escalation gives the plan the best chance of correcting the error before the member is harmed and before it generates a compliance finding. Document everything you know about what happened and when.

A member tells you they received a bill they did not expect based on information you or a colleague gave them

This is a potential grievance. Help the member file a grievance if that is what they want, and route it correctly through your grievance intake process, not as a general service call. Document the member’s complaint and the history of what they were told. Do not dismiss the complaint or tell the member it was their mistake. Escalate to your supervisor so the pattern can be investigated: if one worker gave wrong cost information, others may have too.

Supervisor Tips: Building a Team That Gets Medicare Right

Test Medicare knowledge at hire and annually, not just at onboarding

A new hire who passes a Medicare basics test in week one may give wrong information in week 52 if they have not kept up with annual benefit and regulatory changes. Test Part A, B, C, and D knowledge annually. The CMS annual training requirement is the floor, internal knowledge assessments should go deeper, especially on your plan’s specific benefits and the current plan year’s changes.

Create a culture where looking something up is praised, not penalised

The most dangerous worker is the one who gives wrong information confidently rather than saying “let me check.” Set the expectation explicitly: it is always better to verify than to guess. Monitor call time metrics in a way that does not inadvertently reward wrong answers given quickly over correct answers that took 30 extra seconds to confirm.

Brief the team on annual plan changes before the ANOC mails, not after

Members receive their Annual Notice of Change in late September and immediately call with questions. If your team has not been briefed on the new plan year’s benefit changes before the ANOC mails, they will give members information from the prior year. Brief your team on all benefit changes, cost-sharing, formulary, supplemental benefits, prior auth requirements, at least 30 days before October 15.

Audit call records for accuracy monthly, not just for compliance

Random monthly audits of call recordings reveal what workers are actually saying about Medicare coverage, cost-sharing, and enrollment, not what they say they say. Listen for incorrect Part explanations, wrong cost figures, and missed grievance-versus-appeal triage. Feed findings back into training within the same month. A pattern of wrong answers in one area is a training gap, not a personnel problem.

Worker Checklist: Before, During, and After Every Member Interaction

Before

Benefits change reference card is current for this plan year

Know which enrollment periods are currently open

CRM open and documentation fields ready to complete

During

Verify member ID before discussing any account details

Look up cost-sharing from the member’s benefit summary, never from memory

Triage complaints as grievance or appeal before routing

After

Call record complete, issue type, action taken, resolution

Any corrections or escalations documented with timestamp

Escalations handed off with full context, not just a transfer

Key Takeaways

The four parts of Medicare are not interchangeable, knowing which part covers what is the foundation of doing your job correctly

Part A covers hospital care. Part B covers outpatient care and doctor visits. Part C is Medicare Advantage, the private plan version. Part D covers prescription drugs. These four parts have different cost structures, networks, rules, and enrollment periods. Every member question starts with knowing which part is relevant. Every enrollment decision starts with knowing which period is open.

Giving wrong information is a compliance event, not just a service error

When a plan worker gives a member incorrect cost-sharing information, wrong enrollment period guidance, or incorrect coverage information, the member may make a healthcare decision or an enrollment decision based on that wrong information. That is not a customer service issue, it is a compliance problem that can generate a grievance, an audit finding, and a CMS enforcement action. Accuracy is a compliance standard, not a quality metric.

Checking before answering is the most important skill a Medicare plan worker can have

Medicare is complex, changes annually, and has different rules for different member populations. No one can carry every benefit detail, every enrollment period, and every cost-sharing figure in their head for every plan and every member. The skill that separates a high-quality plan worker from a liability is not knowing everything, it is knowing when to look something up before saying it out loud. That habit protects members and protects the plan.

Frequently Asked Questions

What does Medicare Part A cover and who pays the premium?

Part A covers inpatient hospital stays, skilled nursing facility care after a qualifying hospital stay of at least 3 days, hospice care, and some home health services. Most people pay no premium for Part A if they or a spouse paid Medicare taxes for at least 10 years (40 quarters) of work. People with fewer than 30 quarters of Medicare-covered work pay a full Part A premium; those with 30 to 39 quarters pay a reduced premium. Source: Medicare.gov: Parts of Medicare

What is the difference between Original Medicare and Medicare Advantage?

Original Medicare (Parts A and B) is administered directly by CMS. Members can use any provider who accepts Medicare, with no referrals required and no network restrictions. There is no out-of-pocket maximum in Original Medicare. Medicare Advantage (Part C) is delivered by private insurers approved by CMS. MA plans typically use provider networks, may require referrals for specialists, may require prior authorisation for services, and include an annual out-of-pocket maximum. MA plans often include extra benefits (dental, vision, hearing) not in Original Medicare, and most include Part D drug coverage. Members in Medicare Advantage still pay their Part B premium. Source: Medicare.gov: Medicare Advantage Plans

What are the main Medicare enrollment periods a plan worker needs to know?

Four periods are most important for daily plan operations. The Initial Enrollment Period (IEP) is 7 months around a person’s 65th birthday (3 months before, the birthday month, 3 months after). The Annual Election Period (AEP) runs October 15 to December 7, this is when most members can switch plans. The Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 to March 31 and allows MA members to switch to another MA plan or return to Original Medicare. Special Enrollment Periods (SEPs) allow changes due to qualifying events such as moving to a new service area, losing other coverage, or qualifying for Extra Help. Always confirm which window is open before processing an enrollment or disenrollment. Source: PHLP: Medicare 2025 Enrollment Periods

What is the Part B late enrollment penalty and when does it apply?

If a person does not sign up for Part B when they are first eligible and they do not have a qualifying Special Enrollment Period, they will pay a 10% penalty on their Part B premium for each full 12-month period they went without Part B coverage. This penalty is permanent, it lasts for as long as the person has Part B. For example, if someone waited 2 years after their IEP to enrol in Part B without a valid SEP, their Part B premium is permanently 20% higher than the standard amount. Source: Triage Cancer: 2025 Medicare Quick Guide

What is the Low-Income Subsidy (Extra Help) and how does it affect a member’s Part D costs?

Extra Help (also called the Low-Income Subsidy or LIS) is a federal programme that helps people with limited income and resources pay Part D premiums, deductibles, and copayments. Members with full Extra Help pay little or no Part D premium and have reduced copayments for covered drugs. Members with partial Extra Help receive a sliding scale of assistance. LIS status significantly changes a member’s cost-sharing, a worker who quotes a standard Part D copay to an Extra Help member is giving wrong information. Always check the member’s LIS status before discussing their drug costs. Source: Medicare.gov: Get Help Paying Costs

What changed in Medicare Part D in 2025?

Several significant Part D changes took effect in 2025 under the Inflation Reduction Act. The out-of-pocket cap for Part D was set at $2,000 annually, meaning members will not pay more than $2,000 out of pocket for covered drugs in a year regardless of how many prescriptions they fill. The Medicare Prescription Payment Plan (M3P) allows members to spread their out-of-pocket drug costs across monthly installment payments rather than paying all at once at the pharmacy. The maximum Part D deductible for 2025 is $590. Plan workers handling drug benefit questions must know these caps and be able to explain how they work to members. Source: Triage Cancer: 2025 Medicare Quick Guide

Does a member in Medicare Advantage still have to pay the Part B premium?

Yes. Members enrolled in a Medicare Advantage plan still pay their monthly Part B premium to Medicare, this is in addition to any premium the MA plan charges. The standard Part B premium in 2025 is approximately $185 per month, though higher earners pay more through the Income-Related Monthly Adjustment Amount (IRMAA). Some Medicare Advantage plans offer a Part B premium reduction (also called a giveback benefit) that reduces the amount the member pays for Part B, but the member always pays something toward Part B unless they qualify for a programme that covers it. Never tell a Medicare Advantage member they do not have a Part B premium obligation.

Sources

Government Sources

Medicare.gov: Get Started with Medicare: primary source for Part A, B, C, and D definitions, coverage descriptions, eligibility rules, and enrollment period basics, the official CMS consumer guidance on the Medicare programme.
Medicare.gov: Get Help Paying Medicare Costs: source for Extra Help (Low-Income Subsidy) programme description, eligibility criteria, and how LIS affects Part D cost-sharing for qualifying members.

Reference Sources

Triage Cancer: 2025 Medicare Quick Guide (November 2024): source for 2025 Medicare programme numbers including the Part B standard premium (~$185/month), Part D maximum deductible ($590), Part D out-of-pocket cap ($2,000), and the 10% per year Part B late enrollment penalty structure.
Pennsylvania Health Law Project: Medicare 2025 Webinar Slides: source for the 7-month Initial Enrollment Period structure, enrollment period eligibility rules, and the distinction between IEP, AEP, MA OEP, and SEP enrollment windows.
Medicare Policy in 2025: State of Medicare, August 2025: source for the total Medicare enrolment figure of over 67 million Americans as of mid-2025 and the programme’s role covering approximately one in five Americans and roughly 12% of the federal budget.