Terms Glossary

At Brooks Insurance Group, educating our clients is at the core of what we do. Use this glossary to brush up on important terms.

Enrollment Periods

  • AEP – Annual Enrollment Period

    Oct 15–Dec 7 annually; time to join, switch, or drop Medicare Advantage or Part D plans.

  • OEP – MAOEP – Open Enrollment Period

    Jan 1–Mar 31; allows those in a Medicare Advantage plan to switch MA plans or return to Original Medicare.

  • General Enrollment Period

    January 1 to March 31 annually. For those who missed enrolling in Medicare Part A and/or Part B when first eligible. Coverage begins July 1, and penalties may apply.

  • SEP – Special Enrollment Period

    Allows changes to Medicare plans outside standard periods due to life events like moving, loss of coverage, or gaining Medicaid eligibility.

  • SNP – Chronic, Institutional, Dual Eligible

    A type of Medicare Advantage plan for people with chronic conditions, institutional care needs, or dual eligibility.

Penalties and Premium Adjustments

  • Late Enrollment Penalty

    Fees for enrolling late in Part A (if not free), Part B, or Part D, unless you had creditable coverage.

  • IRMAA – Income-Related Monthly Adjustment Amount

    A higher premium for Part B and Part D based on income.

  • Creditable Coverage

    Prescription drug coverage considered equal to or better than Medicare’s standard—prevents Part D penalty.

Medicare Parts and Plan Types

  • Original Medicare

    Consists of Part A (hospital) and Part B (medical).

  • Part A

    Covers inpatient hospital care, skilled nursing, hospice, and some home health care.

  • Part B

    Covers outpatient care, doctor visits, preventive services, and medical supplies.

  • Part C (Medicare Advantage)

    Offered by private companies; includes Parts A and B, often Part D and extras like dental/vision.

  • Part D

    Stand-alone prescription drug coverage or part of a Medicare Advantage plan.

  • Advantage Plans

    Another name for Part C; includes medical and often drug coverage.

  • Medigap/Supplement Plans

    Private insurance that helps pay for costs not covered by Original Medicare (e.g., coinsurance, deductibles).

Costs and Coverage Terms

  • Premium

    The monthly amount paid for Medicare coverage.

  • Copayment

    A fixed amount paid for a service (e.g., $20 per doctor visit).

  • Deductible

    The amount you must pay before coverage begins.

  • Coinsurance

    A percentage of costs you pay after meeting the deductible.

  • Cost Sharing

    General term for the insured’s share of costs (copays, coinsurance, deductibles).

  • Maximum Out-of-Pocket

    The most you’ll pay in a year for covered services in Medicare Advantage.

  • Medically Approved Amount

    The amount Medicare agrees to pay for a covered service.

  • Medically Necessary

    Services or supplies needed to diagnose or treat a condition per accepted standards.

Plan Structures and Care Access

  • Primary Care Doctor

    The main physician for regular care and referrals.

  • HMO – Health Maintenance Organization

    Requires use of network providers and referrals for specialists.

  • PPO – Preferred Provider Organization

    Offers more provider flexibility, including out-of-network care (often at a higher cost).

  • Network

    Group of doctors, hospitals, and providers contracted with a Medicare plan.

  • Preferred Pharmacy

    Pharmacies with lower cost-sharing in your Part D or Advantage plan.

Low-Income and State Assistance

  • Medicaid

    Joint federal/state program offering health coverage to low-income individuals, including some Medicare beneficiaries (dual eligible).

  • State Pharmaceutical Assistance Programs (SPAPs)

    State programs that help pay Medicare drug plan costs.

  • State Health Insurance Assistance Programs (SHIPs)

    Free counseling and assistance with Medicare choices and issues.

Prescription Drug Plan Structure

  • Deductible Stage

    You pay 100% until your deductible is met.

  • Initial Coverage Stage:

    Your plan pays a portion of drug costs, and you pay the rest (copay or coinsurance).

  • Coverage Gap (“Donut Hole”)

    After reaching a set limit, you pay a higher share for drugs (gradually closing).

  • Catastrophic Stage

    You pay reduced amounts once total out-of-pocket costs reach a set limit.

  • Formularies

    The list of prescription drugs covered by a plan.

  • Tiering

    Classification of drugs (usually 1–5); lower tiers cost less.

  • Preferred Pharmacy

    Offers the lowest copay or coinsurance for covered drugs.

  • Quantity Limits

    Restrictions on how much of a drug you can receive.

  • Step Therapy

    Must try less expensive drugs before coverage for costlier alternatives.

  • Prescription Payment Plan

    Option to spread Medicare drug costs over time.

  • Medicare “Extra Help” / LIS

    A program that helps low-income beneficiaries with Part D costs.

Types of Care and Facilities

  • Skilled Nursing

    Short-term rehab or medical care provided by trained professionals after hospitalization.

  • Inpatient Rehabilitation Facility

    Provides intensive rehab for serious injuries or illnesses.

  • Long-Term Care

    Non-medical care for chronic conditions; generally not covered by Medicare.

  • Hospice

    Care focused on comfort for those with a terminal illness, covered under Part A.

  • Ambulatory Surgical Center

    Outpatient facilities for same-day surgeries.

CMS and Medicare Oversight

  • CMS – Centers for Medicare and Medicaid Services

    Federal agency that runs Medicare and Medicaid.

  • Star Ratings

    Quality ratings (1–5 stars) for Medicare Advantage and Part D plans based on performance.

  • Service Area

    Geographic area where a plan is available and provides coverage.

Annual Notices and Documentation

  • ANOC – Annual Notice of Change

    Sent by Medicare plans each fall to explain changes for the next year.

  • Assignment

    When doctors agree to accept Medicare’s approved amount as full payment.

  • Benefit Period

    Starts when admitted to hospital/skilled nursing and ends after 60 days without care.

  • Lifetime Reserve Days

    60 extra hospital days available after regular Part A benefits are used.

  • Preventive Services

    Screenings, vaccines, and check-ups covered by Medicare to prevent illness.

Special Conditions and Eligibility

  • Beneficiary

    A person enrolled in Medicare.

  • ALS – Amyotrophic Lateral Sclerosis

    Qualifies for automatic Medicare enrollment upon diagnosis.

  • ESRD – End-Stage Renal Disease

    Kidney failure requiring dialysis or transplant; qualifies for Medicare.

Appeals and Protections

  • Advance Coverage Decision

    Request to confirm if a service/item will be covered before you receive it.

  • Appeal

    Request to review and change a denied coverage or payment decision.


    For more information, contact the Centers for Medicare & Medicaid Services.

  • Grievance

    Complaint about a plan’s services, not related to a denial.

  • Guaranteed Issue Rights

    Right to buy Medigap without medical underwriting in specific situations.

  • Guaranteed Renewable Policy

    Insurer cannot cancel your policy if you pay premiums.

  • Medical Underwriting

    Review of health status and preexisting conditions before issuing a Medigap policy (not allowed in some situations).

  • Durable Power of Attorney

    Legal document appointing someone to make health/financial decisions if you're unable.