Primary Care
Your main doctor for routine checkups, preventive care, and general health issues. Often the first doctor you see for any health concern.
Health Insurance Glossary
Plain-language definitions for every health insurance term you'll encounter on Policymage.
Last reviewed: May 29, 2026 · 86 terms · Sources: CMS.gov, IRS.gov, HHS.gov
A
ACA
Affordable Care Act. The federal law (also called Obamacare) that established the ACA Marketplace, required insurers to cover essential health benefits, banned exclusions for pre-existing conditions, and created the premium tax credit subsidy system.
Actuarial Value
The percentage of total average costs a health insurance plan pays for covered services. Bronze plans have 60% actuarial value, Silver 70%, Gold 80%, Platinum 90%. A higher actuarial value means lower out-of-pocket costs but higher premiums.
Aggregate Deductible
On a family plan, a single shared deductible that must be met before coverage kicks in for any family member. Unlike an embedded deductible, no individual cap applies.
Allowed Amount
The maximum payment your insurer will allow for a covered service. If your provider charges more than the allowed amount, you may be responsible for the difference (called balance billing) unless protected by the No Surprises Act.
APTC
Advance Premium Tax Credit. A federal tax credit that reduces your monthly health insurance premium. Based on your household income (100%–400% of the Federal Poverty Level) and the cost of the benchmark Silver plan in your county. You can take it in advance (applied monthly) or as a credit when filing your federal taxes.
B
Balance Billing
When a provider bills you for the difference between their charge and what your insurer pays. Federal law (the No Surprises Act) protects patients from most surprise balance billing by out-of-network providers in emergency situations.
Benchmark Plan
The second-lowest-cost Silver plan available in your county. The federal government uses this plan's premium to calculate your APTC subsidy amount — regardless of which plan tier you actually choose. A higher benchmark = a larger subsidy.
Bronze
Covers about 60% of costs on average. Lowest premiums but highest out-of-pocket costs when you need care. Best if you rarely use medical services.
C
Carrier
Another term for a health insurance company or insurer. The carrier pays claims submitted by providers for your covered health services.
Catastrophic
Very low premiums with very high deductibles. Only available to people under 30 or those with a hardship exemption. Covers worst-case scenarios.
CHIP
Children's Health Insurance Program. A government program providing low-cost health coverage for children in families that earn too much for Medicaid but cannot afford private insurance. In most states, CHIP covers children up to age 19.
Claim
A formal request submitted to your health insurance company for payment of a covered medical service. Claims are typically submitted directly by providers. You receive an Explanation of Benefits (EOB) after a claim is processed.
COBRA
Consolidated Omnibus Budget Reconciliation Act. A federal law allowing employees and their families to continue job-based health insurance coverage after leaving employment. COBRA coverage is usually much more expensive than marketplace coverage because you pay both the employee and employer portions of the premium.
Coinsurance
Your share of costs after you've met your deductible, expressed as a percentage. If your coinsurance is 20%, you pay 20% and insurance pays 80%.
Copay
A fixed dollar amount you pay for a specific service (e.g., $30 for a doctor visit). This amount stays the same regardless of the total bill.
Cost-Sharing
The portion of healthcare costs you pay out of pocket — including deductibles, copays, and coinsurance. Does not include monthly premiums.
CSR
Cost-Sharing Reduction. A subsidy that lowers your deductible, copays, and out-of-pocket maximum. CSR is only available on Silver plans for households earning 100%–250% of the Federal Poverty Level. Creates enhanced Silver variants (Silver 73, Silver 87, Silver 94).
D
Deductible
The amount you pay out of your own pocket each year before your insurance starts covering costs. A $3,000 deductible means you pay the first $3,000.
E
Effective Date
The date your health insurance coverage begins. ACA plans selected during Open Enrollment typically have an effective date of January 1. Plans selected after December 15 usually take effect February 1 or March 1, depending on when you enroll.
EHB
Essential Health Benefits. The 10 categories of services all ACA-compliant individual and small group plans must cover, including hospitalization, prescription drugs, maternity care, mental health services, and preventive care.
Embedded Deductible
On a family plan, a per-person deductible cap within the family deductible. Once any individual hits the embedded deductible, the plan starts paying for that person — even if the full family deductible isn't met.
EOB
Explanation of Benefits. A statement from your insurer showing what medical services were billed, what the insurer paid, and what you owe. An EOB is not a bill — it explains how a claim was processed.
EPO
Exclusive Provider Organization. Similar to an HMO but you typically don't need referrals. Out-of-network care is usually not covered except in emergencies.
Essential Health Benefits
The 10 categories of health services all ACA-compliant plans must cover: ambulatory patient services, emergency services, hospitalization, pregnancy and maternity care, mental health and substance use disorder services, prescription drugs, rehabilitative services, laboratory services, preventive and wellness services, and pediatric services (including dental and vision for children).
F
Family Glitch Fix
A 2022 IRS rule change that allows family members of employees with affordable self-only employer coverage to qualify for ACA Marketplace subsidies if the family premium exceeds affordability thresholds. Previously, the entire family was disqualified based on the employee-only affordability test.
Federally Facilitated Marketplace
Often abbreviated FFM or FFE. The federal exchange operated by CMS at HealthCare.gov. Used by states that have not built their own state-based exchange. Most US states use the FFM.
FFM
Federally Facilitated Marketplace. The federal ACA exchange at HealthCare.gov, operated by CMS. Used by about 30 US states including Texas, Florida, Ohio, Georgia, and North Carolina.
FIPS Code
Federal Information Processing Standards code. A 5-digit code identifying US counties used by the federal marketplace API to look up county-specific plan availability and pricing. The first 2 digits are the state code; the last 3 identify the county.
Formulary
A list of prescription drugs covered by your health insurance plan. Drugs are typically organized into tiers (generic, preferred brand, non-preferred brand, specialty) with different copay amounts per tier. Always check if your medications are on a plan's formulary before enrolling.
FPL
Federal Poverty Level. A measure of income used to determine eligibility for government programs including ACA subsidies. Published annually by HHS. For 2025: $15,060 for 1 person, $20,440 for 2 people, $31,200 for 4 people (48 contiguous states).
FSA
Flexible Spending Account. An employer-sponsored benefit account that lets you set aside pre-tax dollars for qualified medical expenses. Unlike an HSA, FSA funds generally must be used within the plan year (with some grace period or rollover options). Not tied to a specific health plan type.
G
Generic Drugs
Lower-cost versions of brand-name medications that have the same active ingredients and effectiveness. Typically the cheapest prescription option.
Gold
Covers about 80% of costs on average. Higher premiums but lower costs when you need care. Good if you visit doctors frequently.
Grandfathered Plan
A health plan that existed before March 23, 2010 (when the ACA was passed) and has not changed substantially since. Grandfathered plans are exempt from some ACA requirements, including coverage of all Essential Health Benefits and the prohibition on annual limits.
H
HDHP
High-Deductible Health Plan. A health plan with a minimum annual deductible of $1,650 (individual) or $3,300 (family) in 2025. Required to qualify for a Health Savings Account (HSA). HDHP plans typically have lower premiums than traditional plans.
Health Plan ID
A 14-character unique identifier assigned to every ACA Marketplace plan (called HIOS ID). Format: 5-digit issuer ID + 2-digit state + 7-digit plan/variation ID. Used by Policymage URLs to identify specific plans.
HIOS ID
Health Insurance Oversight System Identifier. The 14-character unique ID assigned by CMS to every ACA Marketplace plan. Used to reference plans across the federal marketplace system.
HMO
Health Maintenance Organization. You pick a primary care doctor and need referrals to see specialists. Generally lower premiums but less flexibility.
HSA
Health Savings Account. A tax-advantaged savings account you can use to pay for qualified medical expenses. Only available with high-deductible plans.
HSA Eligible
This plan qualifies for a Health Savings Account, letting you save pre-tax dollars for medical expenses and reduce your taxable income.
I
In-Network
A provider (doctor, hospital, pharmacy) that has a contract with your health insurance plan at negotiated rates. Using in-network providers results in lower costs — you pay your plan's copays and coinsurance rather than full out-of-network rates.
Inpatient
Services that require you to be admitted to a hospital (e.g., surgery, overnight stays). Usually the most expensive type of care.
Issuer
The insurance company that underwrites and issues a health insurance policy. Examples: Blue Cross Blue Shield, Aetna, UnitedHealthcare, Kaiser Permanente, Oscar.
M
MAGI
Modified Adjusted Gross Income. The household income measure used to determine APTC subsidy eligibility. Calculated as AGI plus non-taxable Social Security, tax-exempt interest, and excluded foreign income.
Mail Order Pharmacy
A pharmacy benefit allowing 90-day supplies of maintenance medications to be delivered by mail, often at lower copays than retail pharmacies. Common for ongoing prescriptions like blood pressure or cholesterol drugs.
Mandate
A requirement under the original ACA that most Americans maintain health insurance or pay a tax penalty. The federal penalty was reduced to $0 in 2019 by the Tax Cuts and Jobs Act, though some states (California, Massachusetts, New Jersey, Rhode Island, Vermont, DC) maintain their own individual mandates.
Marketplace
The federally or state-operated exchange where individuals and families can compare and enroll in ACA-compliant health insurance plans and apply for subsidies. Most states use the federal HealthCare.gov marketplace; some states operate their own.
Medicaid
A joint federal-state government health insurance program for low-income individuals and families. Eligibility varies by state. Adults in Medicaid expansion states typically qualify if household income is at or below 138% of the Federal Poverty Level. Medicaid is free or very low cost.
Medicare
Federal health insurance for people 65 and older, certain younger people with disabilities, and people with End-Stage Renal Disease. Medicare is separate from the ACA Marketplace — ACA plans are not available to people enrolled in Medicare.
Modified Adjusted Gross Income
Often abbreviated MAGI. The income measure used to determine ACA subsidy eligibility. Includes adjusted gross income (AGI) plus non-taxable Social Security benefits, tax-exempt interest, and excluded foreign income.
MOOP
Maximum Out-of-Pocket. The most you will pay in a plan year for covered services. Once reached, your insurer covers 100% of covered costs. For 2025, the ACA MOOP limit is $9,200 (individual) and $18,400 (family). Includes deductibles, copays, and coinsurance — but not premiums.
N
Network
The group of doctors, hospitals, and pharmacies your insurance has contracts with. Staying in-network means lower costs for you.
Network Adequacy
A regulatory standard requiring health plans to maintain a sufficient number of in-network providers within reasonable travel distances. CMS and state regulators enforce network adequacy standards for ACA plans.
Network Tier
Some plans organize in-network providers into tiers (e.g., Tier 1: preferred, Tier 2: standard) with different cost-sharing for each tier. Tier 1 providers typically have lower copays.
O
OEP
Open Enrollment Period. The annual window (November 1 – January 15) when anyone can enroll in or change their ACA Marketplace health insurance plan. Plans selected by December 15 take effect January 1.
Open Enrollment
The annual period (November 1 – January 15) during which anyone can enroll in or change ACA Marketplace health insurance plans. Outside open enrollment, you need a qualifying life event for a Special Enrollment Period.
Out-of-Network
A provider that does not have a contract with your health insurance plan. Out-of-network care typically costs significantly more. HMO and EPO plans generally do not cover out-of-network care at all (except emergencies).
Out-of-Pocket Limit
Same as out-of-pocket maximum (MOOP). The cap on your annual cost-sharing for in-network covered services. Once reached, your plan pays 100% of covered services for the rest of the plan year.
Out-of-Pocket Max
The most you'll pay in a year for covered services. Once you hit this limit, your insurance covers 100% of remaining costs.
P
Platinum
Covers about 90% of costs on average. Highest premiums but lowest out-of-pocket costs. Best if you need extensive medical care.
POS
Point of Service. A hybrid of HMO and PPO — you need a primary care doctor and referrals, but you can also go out-of-network at a higher cost.
PPO
Preferred Provider Organization. You can see any doctor without a referral, but pay less if you stay in-network. More flexibility, usually higher premiums.
Pre-existing Condition
A health condition you had before the start of new health insurance coverage. Under the ACA, insurers cannot deny coverage or charge higher premiums based on pre-existing conditions for ACA-compliant plans.
Preventive Care
Health services recommended for generally healthy people to prevent illness or detect conditions early. Under the ACA, most preventive services — including annual physicals, vaccines, mammograms, colonoscopies, and blood pressure screenings — must be covered at no cost (no copay or deductible) on all ACA-compliant plans.
Prior Authorization
A requirement from your insurer that your doctor get approval before you receive certain medical services, tests, or prescription drugs. Without prior authorization for a required service, the insurer may deny the claim.
Provider
Any licensed health care professional or facility that delivers health services. Includes doctors, nurses, hospitals, urgent care centers, labs, and pharmacies.
Provider Directory
A list of all doctors, hospitals, and other providers that participate in a specific health plan's network. Always check the provider directory before enrolling to confirm your preferred doctors are in-network.
Q
Qualifying Life Event
A change in your life situation that makes you eligible for a Special Enrollment Period (SEP) outside of open enrollment. Examples include losing other health coverage, getting married or divorced, having a baby, adopting a child, moving to a new county, gaining citizenship, or leaving incarceration.
R
Reconciliation
The IRS process at tax time where you compare your actual annual income to the income estimate used for APTC subsidies. If your actual income was higher, you may owe back some subsidy. If lower, you may receive an additional credit.
Referral
Written authorization from your primary care doctor to see a specialist. HMO plans typically require referrals; PPO and EPO plans do not. Without a required referral, your insurer may not cover the specialist visit.
S
SBC
Summary of Benefits and Coverage. A standardized 4-page document all health insurance plans must provide, summarizing key plan features: deductibles, copays, out-of-pocket maximum, and coverage examples for common medical events (having a baby, managing Type 2 diabetes, simple fracture).
SBE
State-Based Exchange. A health insurance marketplace operated by an individual state rather than the federal HealthCare.gov. Covers about 20 US states including California, New York, Washington, Pennsylvania, Colorado, and Massachusetts.
SEP
Special Enrollment Period. A window outside the annual open enrollment period during which you can sign up for health insurance. Triggered by qualifying life events such as losing job-based coverage, getting married, having a baby, or moving to a new coverage area.
Short-Term Health Plan
Non-ACA-compliant insurance designed to cover gaps in coverage, typically for less than 12 months. Short-term plans can deny coverage for pre-existing conditions and do not cover Essential Health Benefits. They are not a substitute for ACA coverage and do not qualify you for APTC subsidies.
Silver
Covers about 70% of costs on average. Moderate premiums and moderate out-of-pocket costs. The most popular tier for balanced coverage.
Specialist
A doctor focused on a specific area of medicine (e.g., cardiologist, dermatologist). Some plans require a referral from your primary care doctor.
Specialty Drug
A category of expensive, often biologically complex medications used to treat serious or chronic conditions (cancer, rheumatoid arthritis, multiple sclerosis, hepatitis C). Specialty drugs are placed in the highest formulary tier with the highest cost-sharing.
State-Based Exchange
Often abbreviated SBE or SBM. A health insurance marketplace operated by an individual state rather than the federal government. Examples: Covered California, NY State of Health, Washington Healthplanfinder, Pennie (Pennsylvania).
Step Therapy
Also called 'fail first.' A cost-management practice where insurers require patients to try less expensive drugs before approving coverage of more expensive alternatives. If the first drug fails or causes side effects, the insurer may then authorize the preferred drug.
Subsidy
Financial assistance that reduces health insurance costs. The ACA provides two types: APTC (reduces monthly premiums) and CSR (reduces cost-sharing like deductibles and copays). Eligibility is based on household income as a percentage of the Federal Poverty Level (FPL).
T
Telehealth
Healthcare services delivered remotely via phone or video. Many ACA plans cover telehealth visits at the same or lower copay as in-person primary care visits.
Tobacco Surcharge
An additional premium amount insurers may charge tobacco users — up to 50% more than non-tobacco-user rates under ACA rules. Tobacco surcharges are not eligible for APTC subsidy reduction, so smokers pay the surcharge out of pocket.
U
Urgent Care
Walk-in clinics for non-life-threatening issues that can't wait for a regular appointment (e.g., minor injuries, fever). Cheaper than the ER.