Medicare Abbreviations: Medicare Part D prescription drug plans and Medicare Advantage plans

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Category: Other Q1Medicare tips and questions
Updated: Mar 11, 2025

The complete list of Medicare abbreviations used by the Centers for Medicare and Medicaid Services (CMS) describing Medicare Part D prescription drug plans or Medicare Advantage plans is rather long (about 140 pages or so), so here are a few explanations of our "favorite" acronyms you will probably see as you move through our Q1Medicare.com site and your Medicare plan coverage.

If you have any questions or find a strange acronym, please feel free to email us (Team@Q1Group.com) and we will try to answer your question.

AEP to IRA: Popular Medicare Part D and Medicare Advantage plan abbreviations and acronyms
AEP	Annual Enrollment Period or Annual Election Period - starting October 15th and continuing through December 7th of every year. Read more about the AEP and MA-OEP.
ANOC	The Annual Notice of Change Letter - Your current Medicare plan will send you a letter each year detailing how your Medicare plan will change next year. Remember that your Medicare plan can (and usually does) change the plan's monthly premium, deductible, cost-sharing and drug list (formulary) each year. Your plan's ANOC letter should arrive in late-September or early-October. Learn more about your ANOC letter.
CHAMPVA	Civilian Health and Medical Program of the Department of Veteran Affairs - CHAMPVA prescription drug coverage is considered creditable prescription drug coverage and, if you have CHAMPVA and you join a Medicare Part D prescription drug plan, Medicare will be the primary payer and CHAMPVA will be the secondary payer. You can Learn more about CHAMPVA and Medicare Part D coverage.
CMS	The Centers for Medicare & Medicaid Services - the part of the Federal government that oversees the Medicare Part D and Medicare Advantage program. CMS representatives can be contacted by calling toll-free 1-800-633-4227 (1-800-MEDICARE).
DME	Durable Medical Equipment - Durable Medical Equipment is covered under your Medicare Part B benefits and includes such items as walkers, wheelchairs, and oxygen equipment. Your Medicare Advantage plan may provide alternative coverage for DME and you can refer to your Evidence of Coverage for more information or call your plan's Member Services department (the toll-free number is found on your Member ID card).
DMEPOS	Durable Medical Equipment Prosthetics, Orthotics, and Supplies - DMEPOS includes such items as diabetic testing supplies, prosthetic and orthotic devices and therapeutic shoes, power mobility devices, and respiratory equipment.
EOB	Explanation of Benefits - your Medicare plan will send you an EOB letter each month to explain your Medicare plan usage. Your EOB will show you a detailed list of your spending and your progress toward any plan limits or the phases of your Medicare plan. You can read more about your Explanation of Benefits letter and what is contained in an EOB.
EOC	Evidence of Coverage document - your Medicare plan will provide you with an EOC that may contain 200+ pages of information about your Medicare plan. Your EOC will explain your coverage in detail along with your rights as a Medicare plan member. The EOC will not contain your drug list or formulary.
ESRD	End-Stage Renal Disease (Kidney Failure) - From 2006 through 2020, Medicare Advantage plans could deny access to a non-SNP Medicare plan based on whether a person had ESRD. Instead, people were directed to Medicare Advantage Special Needs Plans (SNPs) specifically designed for people with ESRD (SNP ESRD). Starting back in 2021, any Medicare eligible beneficiary with ESRD can join a Medicare Advantage plan and enrollment applications no longer include the question about the applicant's ESRD. You can use our Medicare Advantage plan finder to see if a Medicare Advantage Special Needs Plan for End Stage Renal Disease is available in your ZIP code.
FAQ	Frequently Asked Question - You can browse our FAQ Section to see some of the more common (and not-so-common) questions about, Medicare and the Medicare Part D and Medicare Advantage programs.
FPL	The Federal Poverty Level - The FPL is set every year and is used to define the Medicare Part D Extra Help Program. If your income level falls below 150% of the FPL, you may be eligible for the Extra Help program or Low-Income Subsidy benefits (or eligible for QMB / SLMB / QI). You can contact your local state Medicaid office for more information about the Extra Help program and how to apply for Extra Help. You can find the current FPL information in our "Medicaid, LIS, & Extra Help" articles.
HICN	Health Insurance Claim Number - The 9-digit and 1 Letter number that appears on your red, white, & blue Medicare card. The HCIN is based on a Social Security number and, as per the Medicare Access and CHIP (Children’s Health Insurance Program) Reauthorization Act (MACRA) of 2015, CMS was required to change the HICN to a unique and random 11-character Medicare Beneficiary Identifier (MBI). From April 2018 through April 2019, Medicare mailed new Medicare cards to the 57.7 million Medicare beneficiaries -- this ended the use of the HICN. You can read more about the new Medicare cards in our article "Your New Medicare Card: What you need to know!"
HMO	Health Maintenance Organization - a type of Medicare Advantage plan, usually with a fairly structured healthcare provider network. Most HMO plans require you to choose a primary care physician (PCP). You may pay more for healthcare coverage and need a recommendation from your PCP if you decide to seek coverage from a specialist or coverage outside of your HMO's healthcare network.
HMO-POS	Health Maintenance Organization with a Point of Service Option - a type of Medicare Advantage plan, with a structured healthcare provider network that may be more flexible than an HMO. An HMO-POS may allow you to move outside of your plan's network, but again, you may pay more for healthcare coverage and the cost of coverage outside of your healthcare network may not count toward reaching your MOOP (or maximum out of pocket threshold). Read more about Medicare Advantage HMO-POS plans.
ICEP	Medicare Advantage plan 7-month Initial Coverage Election Period surrounding your 65th birthday (3 months before your birthday month, the birthday month, 3 months after your birthday month). Please Read more about a Special Enrollment Period (SEP) surrounding your ICEP.
IEP	Medicare Part D Initial Enrollment Period - When you are first eligible for Medicare Part D enrollment you have a 7-month window to join a Medicare Part D plan: the 3-months before your 65th birthday month, your birthday month, and 3-months after your 65th birthday month. But your Part D plan coverage cannot start any earlier than your 65th birthday month.
IRA	Inflation Reduction Act - The Inflation Reduction Act of 2022 (IRA) [P.L. 117-169] includes measures that change Medicare Part D prescription drug plan coverage and costs extending out to 2029 and beyond. In particular, the IRA allows the US government to negotiate drug prices for some of the most popular/expensive medication. Also, the IRA, in 2024 eliminated beneficiary cost-sharing in Catastrophic Coverage and then in 2025 eliminated the Coverage Gap or Donut Hole establishing a maximum out-of-pocket spending limit on formulary prescription drugs (RxMOOP). Learn more about the IRA.

IRMAA to MSP: Popular Medicare Part D and Medicare Advantage plan abbreviations and acronyms
IRMAA	Income-Related Monthly Adjustment Amount - If your modified adjusted gross income (MAGI) exceed certain levels you may be subject to the Income-Related Monthly Adjustment Amount (IRMAA) and pay additional Medicare Part B and Medicare Part D premiums. Learn more about IRMAA.
LEP	Late Enrollment Penalty - The Medicare Part D late-enrollment premium penalty is an additional monthly cost paid by Medicare Part D beneficiaries who did not enroll in a Medicare Part D prescription drug plan when they were first eligible or who were without "creditable" prescription drug coverage for more than 63 days and then choose to enroll in a Medicare Part D plan at a later time. The LEP is a permanent penalty and you will pay your LEP in addition to your monthly premium. Learn more about the Late Enrollment Penalty. Remember that the Medicare Part B program also has a late enrollment penalty.
LIS	Low-Income Subsidy or Medicare Part D Extra Help program - The LIS program helps people with limited financial resources pay for Medicare Part D prescription plan costs including, premiums, deductibles, and copayments. If you qualify for Medicaid, you automatically qualify for the Medicare Part D Extra Help program or LIS. You can contact your local Medicaid office for more information about the LIS program. Learn more about the LIS or Extra Help program.
MA	Medicare Advantage plans without Medicare Part D prescription drug coverage - Caution: In most cases you are not able to add a separate stand-alone Medicare Part D plan (PDP) when you are enrolled in an MA. You can read more about enrolling in an MA HMO and a PDP here. An MA is not the same as a Medicare Advantage plan with Medicare Part D prescription drug coverage (MAPD) see below.
MADP (pre-2019)	Medicare Advantage Disenrollment Period - Since 2019, there is no longer a Medicare Advantage Disenrollment Period (MADP) and instead, Medicare created the Medicare Advantage Open Enrollment Period (MA-OEP). The MA-OEP runs every year from January 1st through March 31st. A bit of history. . . here is the MADP information from pre-2019: Even though you are outside of the AEP (that closed December 7th), you can leave your Medicare Advantage plan from January 1st through February 14th and return to Original Medicare Part A and Medicare Part B - and enroll in a stand-alone Medicare Part D plan (PDP). You can read more about the MA-OEP and the old MADP.
MAGI	Modified Adjusted Gross Income - The Social Security Administration uses your MAGI (as reported by the Internal Revenue Service) to determine your IRMAA (income-related monthly adjustment amount). You can learn more about your MAGI and IRMAA here.
MA-OEP	In 2019, Medicare established the Medicare Advantage Open Enrollment Period (MA-OEP) that replaced the Medicare Advantage Disenrollment Period (MADP). The MA-OEP allows people “enrolled in an MA plan, including newly MA-eligible individuals, to make a one-time election to go to another [Medicare Advantage] plan” - or to leave their Medicare Advantage plan, join a stand-alone Medicare Part D plan [PDP], and return to Original Medicare Part A and Part B. "For example, an individual enrolled in an MA-PD plan may use the [MA-]OEP to switch to: (1) another MA-PD plan; (2) an MA-only plan; or (3) Original Medicare with or without a PDP. The [MA-]OEP will also allow an individual enrolled in an MA-only plan to switch to-- (1) another MA-only plan; (2) an MA-PD plan; or (3) Original Medicare with or without a PDP. However, this enrollment period does not allow for Part D changes for individuals enrolled in Original Medicare, including those with enrollment in stand-alone PDPs." As a historical note: In past years, you may have seen the term, "annual Open Enrollment Period" used interchangeably with the Annual Election Period (AEP) or Annual Coordinated Election Period describing the annual Medicare Part D and Medicare Advantage plan enrollment period starting October 15th and continuing through December 7th. Please be sure to recognize the [MA-]OEP as the Medicare Advantage Open Enrollment Period - not to be confused with the AEP. Please note: Some organizations are using the term OEP to refer to the AEP and also the MA-OEP.
MAPD	Medicare Advantage plan with Medicare Part D prescription drug coverage - You can read more about MAs and MAPDs.
MBI	Medicare Beneficiary Identifier - As per the Medicare Access and CHIP (Children’s Health Insurance Program) Reauthorization Act (MACRA) of 2015, CMS was required to by changed to a unique and random 11-character MBI that will be shown on Medicare cards. Originally, a 9-digit and 1 letter Health Insurance Claim Number (HCIN) appears on red, white, & blue Medicare cards. The HCIN is based on a Social Security number and represents an easy target for identity theft and fraud. From April 2018 through April 2019, Medicare mailed new Medicare cards to 57.7 million Medicare beneficiaries and end the use of the HICN. You can read more about the new Medicare cards in our article, "Your New Medicare Card: What you need to know!"
Medigap	Medicare Supplements - Medigap plans are private insurance policies that provide additional benefits to your original Medicare Part A and Medicare Part B coverage. Medigap plans are administered by your state and come in different variations that are, for the most part, standardized across the country (although some states offer their own variations). Medicare Supplements or Medigap plans are not Medicare Advantage plans and do not work together with Medicare Advantage plans. Medigap plans charge a monthly premium (that can change year-to-year) and cover some of the additional costs above your Medicare coverage (depending on your chosen Medigap policy). Medigap policies are offered as guaranteed issue (with no health underwriting) when you first become Medicare eligible - but, (depending on your state) if you try to later join a Medicare Supplement, your coverage may be denied, or pre-existing health issues may not be covered, or you may pay a higher premium based on your health.
MOOP	Maximum out-of-pocket spending limit - If you are enrolled in a Medicare Advantage plan, you will have a MOOP that limits the amount that you will spend on Medicare Part A (in-patient, hospital) costs and Medicare Part B (out-patient, doctor visit) costs. Once you meet your MOOP, you will not pay more for any covered Medicare coverage. MOOP does not included Medicare Part D prescription drug costs (TrOOP). Your MOOP limit can change every year. You can click here to read more about MOOP and TrOOP.
MSA	Medicare Medical Savings Account - MSAs combine a high-deductible Medicare Advantage plan and a bank account. The Medicare plan deposits money from Medicare into your savings account. You can use the money into pay for your health care costs. However, only Medicare-covered expenses count toward your deductible. Please note that MSA plans are not available everywhere. In 2025 MSAs are only available to residents of Wisconsin as compared to 2023 when MSAs were available in 2,313 counties across 37 states.
MSP	Medicare Savings Programs (QMB, SLMB, and QI) - MSPs are state Medicaid programs that help people with limited financial resources pay some or all of their Medicare premiums, deductible, and cost-sharing. Learn more about MSPs.

NDC to TrOOP: Popular Medicare Part D and Medicare Advantage plan abbreviations and acronyms
NDC	National Drug Code - The NDC uniquely identifies a particular drug, manufacturer, strength, and packaging combination. The NDC is often shown on your prescription bottle as an 11-digit code or could be formatted as 00000-0000-00 where the first set of numbers identifies the manufacturer, the second set of number identifies the product and strength, and the third set of numbers identifies the packaging. Please remember that the assignment of a National Drug Code (NDC) (or National Health Related Item Code (NHRIC)) does not in any way denote United States Food and Drug Administration (FDA) approval of the prescription drug. You can search by NDC (ex: 60505257808) for a drug in our Q1Rx.com/CA/60505257808 Drug Finder.
OTC	Over-the-counter drugs - OTC medications are the drugs that you typically purchase without a prescription such as cough syrup or generic aspirin. Some OTC drugs also come in different forms that require a prescription. The Medicare Part D prescription drug program does not cover OTC medications. However, some Medicare Part D plans provide some coverage (or limited coverage) of OTC drugs as an additional benefit to their Medicare Part D plan. If a Medicare plan does provide coverage for OTC drugs, the costs of the OTC drugs does not count toward reaching any of your out-of-pocket (TrOOP) threshold (RxMOOP).
PA	Prior Authorization - You may be required to receive prior Medicare plan approval before using a specific medication or seeking specific healthcare services. For example, on your Medicare Part D plan formulary, you may notice "PA" printed next to a specific medication. If you were to fill a prescription without Prior Approval, your Medicare plan may not pay for the coverage of this medication. In this case, the PA is a Drug Usage Management Restriction and you can appeal your Medicare plan's PA requirements. Prior Authorization, Quantity Limits, and Step Therapy requirements are shown in both our Formulary-Browser.com and Q1Rx.com Drug Finder.
PACE	Program of All-Inclusive Care for the Elderly - Special types of Medicare health plans with Medicare Part D prescription drug coverage, Medicare Part A (in-patient coverage), Medicare Part B (outpatient coverage), and may include additional benefits from Medicare and Medicaid - depending on your state. You can contact your local Medicaid office to learn more about PACE.
PCP	Primary Care Physician - If you enroll in a Medicare Advantage plan (such as an HMO or HMO POS), your Medicare plan may require that you have a doctor or other healthcare provider that you see first for most of your health problems. A PCP will work to coordinate your healthcare and they will be the person providing a reference to another doctor, healthcare provider, or specialist based on your specific needs. Your Medicare plan may require that you get approval from your PCP for most medical care - with limited exceptions.
PDP	A stand-alone Medicare Part D prescription drug plan that provides drug coverage only (Rx only) - Sometimes a PDP may also cover non-Medicare Part D drugs as Bonus Drugs or over-the-counter drug (OTC) as an added benefit, however it does not cover healthcare. You can use our PDP-Finder to see all stand-alone Medicare Part D plans in your area. You can also click here to learn more about how a PDP compares to an MAPD.
PFFS	Private Fee-for-Service - Medicare Advantage plans with no established healthcare network. You are able to visit any healthcare provider who accepts Medicare and the terms and conditions of your PFFS plan. PFFS plans were popular at one time, but with changes in network requirements, PFFS plans are no longer available in many areas. Learn more about PFFS plans.
PPO	Preferred-Provider Organizations - Medicare Advantage plans with a more flexible healthcare network. If you seek healthcare outside of the Medicare PPO plan's network, you can expect to pay a higher cost-sharing. You can read more about Medicare Advantage PPOs and you can learn more about how a Medicare Advantage PPO compares to an HMO-POS plan.
Q1Rx®	Q1Rx Drug Finder - The Q1Rx® Drug Finder is an online tool allowing you to quickly compare how all Medicare Part D prescription drug plans (PDPs) or Medicare Advantage plans that include drug coverage (MAPDs) in your service area (state or ZIP) cover a particular prescription drug. You can click here to read more about the Q1Rx Drug Finder. (Q1Rx is exclusive to the Q1Medicare site and is not an "official" Medicare acronym.)
QI	Qualified Individual - The QI program is a state Medicare Savings program that helps people with low income and limited assets pay their Medicare Part B premiums. You can click here to read more about the QI program.
QL	Quantity Limits - Your Medicare Part D prescription drug plan may limit the quantity of a particular medication during a specific time. For example, you may find that your Medicare plan has a QL of 30 pills for 30 days. The QL is a Drug Usage Management Restriction imposed by your Medicare plan to protect plan members from drug over-usage. If you need a larger quantity than your QL, you (and your doctor) can to ask your Medicare plan for a Coverage Determination (Formulary Exception) whereby your Medicare plan will provide coverage for your prescription that is over the Quantity Limit. If your exception request is denied, you can appeal your Medicare plan's QL determination. Prior Authorization, Quantity Limits, and Step Therapy requirements are shown in both our Formulary-Browser.com and Q1Rx.com Drug Finder.
QMB	Qualified Medicare Beneficiary - The QMB program is a state Medicare Savings program that helps people with low income and limited assets pay their Medicare Part A and Medicare Part B premiums - plus deductibles and cost-sharing (copayments and coinsurance). You can click here to read more about the QMB program.
RxMOOP	Maximum out-of-pocket spending limit for covered prescription drugs - The RxMOOP (not an "official" Medicare acronym) was introduced in the Inflation Reduction Act of 2022 where the government eliminated beneficiary cost-sharing in the Catastrophic Coverage phase in 2024 and then in 2025, eliminated the Coverage Gap by establishing an annual maximum out-of-pocket spending limit for prescription drugs found on a drug plan's formulary. Since 2024, the TrOOP threshold is equivalent to the RxMOOP. In 2025, the RxMOOP is $2,000 ($2,100 in 2026). You can click here to read more about the RxMOOP.
SEP	Special Enrollment Periods allow you to join, change, or drop your Medicare Part D or Medicare Advantage plan outside of the Annual Enrollment Period (that ends each year on December 7th). Read more about different SEPs that may be available to you.
SLMB	Special Low-Income Medicare Beneficiary - Like the QI and QMB program, the SLMB program is a state Medicare Savings program that helps people with low income and limited assets who have Medicare Part A pay their Medicare Part B premiums. You can click here to read more about the SLMB program.
SNF	Skilled Nursing Facility - the Medicare.gov site provides a nice description of how Medicare coverage applies to a SNF: www.medicare.gov/coverage/skilled-nursing-facility-snf-care
SNP	Medicare Advantage Special Needs Plans - Medicare Advantage plans designed to provide specialized health care for people with specific needs such as people who are dual eligible for both Medicare and Medicaid, live in a nursing home or long-term care facility, or have certain chronic medical conditions (such as diabetes). SNPs are not available everywhere and you will need to check to Medicare Advantage plans in your area to see if a SNP offered. Also, you are only allowed to join (and stay in) a SNP if you meet the special need (so you cannot not join a Dual-Eligible SNP without meeting the financial requirements). You can click here to read more about Medicare Advantage SNPs.
SPAP	State Pharmaceutical Assistance Program - SPAPs are State programs that provide assistance paying for prescription drug coverage based on finances, age, and medical need. You will need to check with your state to see if a SPAP is available. Learn more about SPAPs.
TrOOP	Total (or True) out-of-pocket cost - TrOOP includes everything that you spend on formulary prescription drugs (or that someone spends on your behalf) - but TrOOP does not include your monthly plan premiums. The TrOOP threshold is the amount of money you need spend before entering into the Catastrophic Coverage phase of your Medicare Part D prescription drug coverage. The 2022 Inflation Reduction Act (IRA) eliminated beneficiary cost-sharing in the Catastrophic Coverage in 2024 and then eliminated the Coverage Gap or Donut Hole in 2025 establishing a maximum out-of-pocket spending limit on formulary prescription drugs (RxMOOP) that effectively replaces the TrOOP threshold. Learn more about TrOOP.