CheapestACA Plans

ACA glossary

Plan year 2026, last refreshed 2026-04-19T08:08:55.462Z.

Plain-English definitions of the terms that show up in plan listings, the subsidy math, and the regulations behind both. Each entry has a regulatory or canonical reference where one exists.

ACA (Affordable Care Act)
Patient Protection and Affordable Care Act of 2010 (Pub.L. 111-148). The federal law that created the Health Insurance Marketplace, premium tax credits, essential health benefits, the individual market guaranteed-issue rule, and Medicaid expansion.
APTC (Advance Premium Tax Credit)
Federal premium subsidy advanced to the insurer monthly on the household's behalf. Codified at 26 USC §36B with implementing regulations at 26 CFR §1.36B. Computed against the second-lowest-cost Silver plan available to the household, using the IRS contribution-percentage table (Rev. Proc. 2025-25 for PY2026).
FPL (Federal Poverty Level)
HHS-published income thresholds (annual) used to determine ACA subsidy eligibility. Three tiers: 48 contiguous states + DC, Alaska (higher), Hawaii (higher). PY2026 coverage uses the 2025 FPL table (90 FR 5036, published January 2025).
Benchmark Silver
The second-lowest-cost Silver-tier plan available to the household in their county and rating area. Used by 26 USC §36B as the basis for APTC: APTC = max(0, benchmarkAnnual − income × applicablePct). The user can apply the credit to any plan they pick, not just the benchmark.
EHB (Essential Health Benefits)
The 10 categories of services every ACA-compliant individual-market plan must cover (45 CFR §156.110): ambulatory, emergency, hospitalization, maternity, mental health, prescription drugs, rehab, lab, preventive, pediatric. Plans with non-EHB add-ons (§1303 abortion rider, adult dental, vision) carry an EHB-percent below 1.0 and the non-EHB portion is not APTC-eligible.
EHB% / EHB-percent
Per-plan attribute (EHBPercentTotalPremium in the CMS Plan Attributes PUF) representing the fraction of the gross premium that pays for Essential Health Benefits. Used to cap applied APTC: applied = min(monthlyAptc, gross × ehbPercent). Per 26 CFR §1.36B-3(c)(3)(iii).
Metal tier
Plan category by actuarial value (the % of total covered medical costs the plan pays on average): Bronze (60%), Silver (70%), Gold (80%), Platinum (90%). Catastrophic is a separate, lower-AV tier with eligibility limited to under-30 or hardship-exempt enrollees. "Expanded Bronze" is a regulatory variant introduced by the 2017 final rule.
Bronze plan
Lowest-AV ACA metal tier (60% actuarial value). Lowest gross premium typically; highest deductible and out-of-pocket cost when you actually use care. Best fit for healthy households who want the cheapest premium and rarely use the system.
Silver plan
Mid-AV ACA metal tier (70%). The benchmark for APTC math (26 USC §36B). Households 100-250% FPL on Silver also qualify for cost-sharing reductions (CSR) per §1402, which raise the effective AV to 73-94%. Silver is often the best net-premium choice for subsidized households.
Gold plan
Higher-AV ACA metal tier (80%). Higher gross premium than Silver but lower deductibles and OOP costs at point of care. Often the best total-cost option for households with predictable medical use, especially in markets where the Gold-Silver premium spread is narrower than the AV difference.
Platinum plan
Highest-AV ACA metal tier (90%). Rarely the cheapest and rarely the best total-cost option except for very high utilizers. Not all states have Platinum carriers (FL/TX have very few).
Catastrophic plan
ACA plan tier with AV below 60%, designed for low-utilization enrollees. Federally limited to under-30 enrollees or those with a hardship/affordability exemption (45 CFR §156.155). Not APTC-eligible. California adds state-specific restrictions for adults 30+.
Deductible
Annual amount the enrollee pays before the plan starts paying for most services. Plans with HSA-eligibility have higher minimum deductibles set by the IRS (PY2026: $1,650 single / $3,300 family).
MOOP (Maximum Out-Of-Pocket)
Annual cap on what the enrollee pays for in-network covered services (deductible + copays + coinsurance). Once you hit MOOP, the plan pays 100% of in-network covered services for the rest of the plan year. Federal limit for PY2026: $9,200 single / $18,400 family (45 CFR §156.130).
On-exchange / off-exchange
On-exchange plans are sold through HealthCare.gov or a state marketplace and qualify for APTC and CSR. Off-exchange plans are the same ACA-compliant policies sold directly through carriers; they are NOT APTC-eligible. Some plans are sold both on and off exchange.
Rating area
State-defined geographic unit (typically a group of counties) used by carriers to file rates. One plan can have different filed rates across rating areas in the same state. Alaska, Massachusetts, and the LA region of California have multi-rating-area resolutions inside a single FIPS.
FIPS code
Federal Information Processing Standards code identifying a US county. Five digits, zero-padded (e.g. Travis County, TX = 48453, not 48000). The canonical jurisdiction key for plan availability.
OEP (Open Enrollment Period)
Annual window when anyone can enroll in or change ACA coverage without a qualifying event. Federal marketplace OEP runs Nov 1 → Jan 15 for the following plan year. State exchanges set their own dates (e.g. CA: Nov 1 → Jan 31).
SEP (Special Enrollment Period)
Triggered window outside OEP when a qualifying life event (loss of coverage, marriage, birth, move, income change for current enrollees, etc.) lets you enroll or change plans. Most SEPs last 60 days. See our SEP qualifying-events page.
SBC (Summary of Benefits and Coverage)
4-page standardized cost-sharing disclosure required of every ACA plan (45 CFR §147.200). Contains the deductible, MOOP, and copay/coinsurance for ~30 standard service categories. Carriers publish SBC PDFs; we extract them per-plan to enrich plan detail.
Medicaid expansion
ACA provision allowing states to extend Medicaid eligibility to adults under 138% FPL. Funded mostly by the federal government. As of 2026, 41 states + DC have expanded; 10 have not (the 'coverage gap' for adults below 100% FPL who don't qualify for either Medicaid or APTC).
CSR (Cost-Sharing Reductions)
Additional federal subsidy (separate from APTC) for households 100-250% FPL who pick a Silver plan on-exchange. Raises the effective actuarial value of Silver to 73% (200-250% FPL), 87% (150-200%), or 94% (100-150%). Applied automatically by the insurer; no user action required.
Tobacco surcharge
Federal law (45 CFR §147.102(a)(1)(iv)) lets ACA plans charge tobacco users up to 1.5x the non-tobacco rate. State law can prohibit or cap the surcharge: as of PY2026, 9 jurisdictions ban it (CA, MA, NJ, NY, RI, VT, DC, MD, NM); 3 cap below 1.5x (CO, KY, AR); the rest follow federal default. Default pricing on this site is non-tobacco; the search form has an opt-in tobacco toggle that reprices each plan with the carrier's filed surcharge.
Hardship exemption
Federal exemption that lets adults 30+ enroll in a Catastrophic plan (normally limited to under-30 enrollees per 45 CFR §156.155). Must be granted by the marketplace based on a hardship category (homelessness, eviction, domestic violence, bankruptcy, ineligibility for Medicaid in a non-expansion state, the lowest Bronze costing >8.05% of income, etc.). Application is at HealthCare.gov/exemptions or the equivalent state-exchange page.
HDHP / HSA-eligible plan
High-Deductible Health Plan with a deductible and OOP max meeting the IRS thresholds (PY2026: deductible ≥ $1,650 single / $3,300 family; OOP ≤ $8,300/$16,600). Pairs with a Health Savings Account (HSA) for triple-tax-advantaged contributions. Most Bronze and many Silver plans qualify; we tag HSA-eligible plans with a badge in plan listings.
NPN (National Producer Number)
Six- or seven-digit identifier the National Insurance Producer Registry (NIPR) issues to every licensed insurance agent and broker. CMS Model Consent and state-broker-of-record filings reference the NPN. Verify any broker's NPN at nipr.com/help/look-up-your-npn before signing a Broker of Record form.

More on the math behind these numbers in our methodology page. Quick lookup of qualifying-event SEPs at our SEP guide.