State-Based Marketplaces vs. HealthCare.gov: Which Enrollment Portal Applies to You

Why Two Different Systems Exist

When the Affordable Care Act (ACA) became law in 2010, it gave each state a choice: build and operate your own health insurance exchange, or let the federal government run one for you. The result is a patchwork system — and unless you know which type of marketplace your state uses, you could end up on the wrong website, wasting critical enrollment time.

Think of it this way: the ACA set the rules of the game (plan requirements, subsidy formulas, consumer protections), but it let states decide who manages the playing field. Some states jumped at the chance to customize their exchange. Others, either due to political opposition or limited resources, opted into the federally facilitated marketplace instead.

As of 2024, roughly 18 states and the District of Columbia operate fully state-based marketplaces. The remaining states — about 30 — use HealthCare.gov as their enrollment platform. There's also a small middle group: state-based marketplaces using the federal platform (SBM-FPs), where a state technically runs its own exchange but relies on HealthCare.gov's technology to process enrollments.

Understanding this distinction isn't just trivia. It affects your enrollment deadline, which financial assistance programs you can access, and even the customer support number you should call when something goes wrong. For a fuller picture of how ACA plans themselves work, see our overview of ACA marketplace plans.

HealthCare.gov: How the Federal Marketplace Works

If you live in a state that uses HealthCare.gov, the enrollment process is straightforward: you visit HealthCare.gov, create or log into your account, enter your household information, and shop for plans. The site automatically calculates your eligibility for the PTC — the main federal subsidy that lowers your monthly premium — and shows you plans after applying your estimated credit.

Key Features of HealthCare.gov

• Centralized platform: One website handles enrollment, subsidy applications, plan comparisons, and renewals for all participating states.
• Federal open enrollment window: November 1 through January 15 (for most states using HealthCare.gov). Enroll by December 15 for coverage starting January 1.
• Medicaid referrals: If your income falls below the subsidy threshold, HealthCare.gov refers you to your state's Medicaid agency — but the two systems are separate.
• Navigator and broker access: Federally funded navigators and licensed brokers can assist you at no cost through the HealthCare.gov platform.

One thing HealthCare.gov cannot do: offer state-funded supplemental subsidies. You get exactly what federal law provides — no more, no less. If your state has chosen to layer on additional financial help, you won't find it here.

For a deeper walkthrough of the enrollment steps on HealthCare.gov, our step-by-step enrollment guide covers every screen from account creation to plan confirmation.

State-Based Marketplaces: What They Offer Differently

State-based marketplaces (SBMs) are independently operated exchanges that meet all federal ACA requirements but also have the authority to go beyond them. Think of them as the ACA's framework with local upgrades.

Examples of Active State-Based Marketplaces

• Covered California (California)
• NY State of Health (New York)
• Connect for Health Colorado (Colorado)
• Massachusetts Health Connector (Massachusetts)
• Access Health CT (Connecticut)
• Washington Healthplanfinder (Washington State)
• MNsure (Minnesota)

Each of these portals has its own web address, its own customer service team, and sometimes its own enrollment calendar. Visiting HealthCare.gov when you live in California, for example, will redirect you to Covered California — the federal site itself will tell you to go elsewhere.

Where SBMs Commonly Go Further

1. Extended enrollment deadlines: Massachusetts, for instance, has an almost continuous enrollment window due to its longstanding state health reform history. New York and California typically extend past the federal January 15 cutoff.
2. State subsidy programs: California's state-funded premium assistance (separate from the federal PTC) can bring costs down to near zero for lower-income enrollees. New York offers the Essential Plan for people slightly above Medicaid eligibility.
3. Tighter Medicaid integration: Several SBMs allow a single application to screen for both marketplace plans and Medicaid simultaneously, streamlining the process.
4. Additional plan requirements: Some states require insurers to cover benefits beyond the ACA's Essential Health Benefits — such as broader reproductive health services or enhanced mental health parity.

To understand the broader open enrollment timeline that both systems follow as a baseline, our article on the ACA marketplace open enrollment window explains federal deadlines in detail.

How to Find Out Which Portal Applies to You

This is simpler than most people expect. Follow this quick checklist:

Step-by-Step: Identify Your Enrollment Portal

1. Go to HealthCare.gov and enter your ZIP code. If your state has its own marketplace, the site will redirect you automatically. That redirect URL is your actual enrollment portal.
2. Check the CMS list. The Centers for Medicare & Medicaid Services (CMS) publishes an updated list of which states use HealthCare.gov versus their own exchange. Search "CMS state marketplace type" to find the current version.
3. Look for a state-branded URL. If your enrollment site ends in a state agency domain (e.g., coveredca.com, nystateofhealth.ny.gov), you are on a state-based marketplace.
4. Call your state's insurance department. If you're still unsure, your state's department of insurance can confirm which platform handles ACA enrollment.

The Hybrid Category: SBM-FPs

A few states occupy a middle ground. States like Nevada and New Mexico have their own marketplace brands and set their own policies, but they process enrollments through HealthCare.gov's technology. In practice, you may be directed to a state-branded page that is powered by the federal system behind the scenes. For enrollment purposes, follow wherever HealthCare.gov sends you — the correct portal will appear.

If you're weighing a marketplace plan against job-based coverage, our comparison of employer vs. ACA marketplace enrollment walks through how the two processes differ.

Enrollment Timelines: Where They Match and Where They Diverge

Federal law sets a baseline open enrollment period for all ACA exchanges: November 1 through January 15 in most years. But state-based marketplaces have the authority to extend this window — and many do. Here's what that looks like in practice:

Standard Federal Enrollment Calendar (HealthCare.gov States)

• November 1: Open enrollment begins. You can browse, compare, and enroll in plans.
• December 15: Deadline to enroll for coverage starting January 1.
• January 15: Final deadline. Coverage begins February 1 for plans selected after December 15.

State Variations to Know

• California (Covered California): Open enrollment typically runs through January 31, giving residents an extra two weeks.
• New York (NY State of Health): Enrollment often extends through January 31 as well.
• Massachusetts (Health Connector): Massachusetts operates under a near-continuous open enrollment due to its state mandate, with specific deadlines tied to coverage start dates.
• Washington, DC (DC Health Link): DC frequently extends its window into late January or early February.

Missing the open enrollment window doesn't necessarily leave you uninsured. A qualifying life event — such as losing job-based coverage, getting married, or having a baby — triggers a Special Enrollment Period (SEP). Learn more about which events qualify in our special enrollment hub.

For a comprehensive view of the entire marketplace experience from eligibility through plan selection, see The Health Insurance Marketplace from Start to Finish.

Subsidies, Plan Options, and What Stays the Same

Here's something many people don't realize: the core rules don't change based on which portal you use. Whether you enroll through HealthCare.gov or Covered California, the following federal standards apply equally:

• Metal tiers: All marketplaces offer Bronze, Silver, Gold, and Platinum plans with standardized actuarial value requirements.
• Essential Health Benefits (EHBs): Every plan must cover the 10 EHB categories, including preventive care, mental health services, and prescription drugs.
• Premium Tax Credits (PTCs): Federal subsidies are calculated using the same income-to-federal-poverty-level formula nationwide. Your credit amount doesn't depend on which portal you use.
• Cost-Sharing Reductions (CSRs): If you qualify for CSRs (generally 100–250% of the federal poverty level), you must enroll in a Silver plan on a marketplace — any marketplace — to receive them.
• No coverage denials for pre-existing conditions: This ACA protection applies on every exchange.

Where differences emerge is in the additional programs layered on top by state-based marketplaces. California, New York, Colorado, and others have used state funds to create programs that reduce costs further for residents who might not qualify for large federal subsidies but still struggle with premiums.

For example, New York's Essential Plan serves adults from 138% to 200% of the federal poverty level with very low premiums — a benefit that exists only because New York operates its own marketplace and chose to invest state Medicaid waiver dollars into it.

To explore all the plan options available to you through any marketplace, our marketplace plans hub covers metal tiers, network types, and how subsidies stack against plan costs.

If you're new to this process entirely, take a step back and review our full marketplace walkthrough before your first enrollment session. Going in prepared saves significant time and reduces the chance of a costly mistake.