Common ACA Marketplace Mistakes (and How to Avoid Them)

Why Marketplace mistakes are so common

The application is the easy part. HealthCare.gov walks you through income, household, and plan selection in an afternoon. What it cannot do is read a provider directory for you, check a drug list against your medicine cabinet, or predict what your income will actually be next December.

That is where the mistakes live — not in the form fields, but in the comparison steps that get skipped and the follow-through that never happens. Many of these mistakes are not obvious during enrollment and may surface later through higher costs, denied claims, repayment obligations, or inactive coverage.

The good news is that many of these mistakes may be reduced through careful comparison and follow-through. Here are nine common mistakes worth checking for.

Mistake 1: Misestimating your income

The Marketplace asks for an estimate of this year’s expected income — not what last year’s tax return showed. That estimate drives the advance premium tax credit, and the credit is reconciled on the federal tax return for that year.

Estimate too low, and the household may have to repay excess advance premium tax credits when filing the federal return. For 2026 and later tax years, the prior income-based repayment limitations no longer apply, so the full excess advance credit may generally be added to the household’s tax liability. Estimate too high, and the household may pay more premium during the year than necessary, although an eligible taxpayer may claim any additional allowable premium tax credit when filing the federal return. Careful estimates and prompt Marketplace updates remain important in both directions.

For self-employed and 1099 households, this can be one of the most important fields on the application because projected net income may fluctuate. Our guide on what income to report walks through it in detail.

Mistake 2: Shopping on premium alone

The monthly premium is the most visible number on the screen, so it becomes the sorting key — and the decision. But a premium is only one input into what a plan costs a household.

Depending on the plan design, a lower premium generally pairs with higher cost-sharing: a larger deductible, higher copays or coinsurance, or both. For a household that rarely uses care, that trade can make sense. For a household with regular prescriptions, ongoing treatment, or children who visit the doctor often, the “cheap” plan may produce substantially higher total annual costs once medical care or prescriptions are used.

The useful comparison covers the deductible, copays, and coinsurance, the out-of-pocket maximum, the network, and the drug list — weighed against how your household actually uses care.

Mistake 3: Assuming your doctors are in-network

Networks belong to plans, not carriers. Two plans from the same insurer, in the same county, can run different networks — and a doctor who was in-network last year may not be this year.

The reliable check is to verify each provider — primary care, specialists, and the hospital you would actually use — against the exact plan’s current directory before enrolling, and to confirm directly with the provider’s office when a relationship matters. Our guides on provider networks and HMO vs. PPO plans cover how network type changes what out-of-network care costs.

Mistake 4: Skipping the prescription check

Prescription drugs are an essential health benefit category, so ACA-compliant plans generally include drug coverage — but each plan’s formulary decides which medications it covers, on what tier, and with what requirements such as prior authorization or step therapy.

The mistake is checking no medications, or checking only the expensive one. Check every medication in the household against each plan’s current formulary before enrolling. Our article Are My Prescriptions Covered by an ACA Plan? walks through exactly how.

Mistake 5: Overlooking Silver cost-sharing reductions

Households within certain income ranges may qualify for standard income-based cost-sharing reductions — lower deductibles, copays, coinsurance, and out-of-pocket maximums — but these standard reductions generally require enrollment in a Silver Marketplace plan. Separate cost-sharing protections may apply to eligible American Indians, Alaska Natives, and certain ANCSA shareholders.

A household that qualifies and enrolls in a Bronze plan to save premium, or a Gold plan for richer benefits, generally does not receive them. For many CSR-eligible households, a Silver plan effectively delivers benefits closer to a higher metal tier at a Silver price point — which is why checking CSR eligibility before comparing metal tiers is the correct order of operations.

Mistake 6: Auto-renewing without a review

If you take no action during Open Enrollment, the Marketplace may automatically re-enroll you in the same plan or a similar one. Convenient — and quietly risky.

Premiums, provider networks, drug lists, plan designs, and plan availability can all change from one plan year to the next, and an outdated income estimate can change the credit. The plan that fit last year may not be the best fit this year, and in some cases it may not exist this year in the same form. A short annual review during Open Enrollment — even one that ends with keeping the same plan — is generally the cheapest insurance against all of it.

Mistake 7: Not reporting changes during the year

The Marketplace application is a snapshot; life is not. Changes in expected income, household size, marriage or divorce, a birth or adoption, a move, or a new offer of other coverage can all affect the premium tax credit — and some may create a Special Enrollment Period under the applicable rules.

Reporting changes promptly keeps the advance credit aligned with actual income, which generally shrinks any adjustment at tax time, and it preserves enrollment options that come with deadlines attached. Waiting until tax season to reconcile a year of unreported changes is how a subsidy becomes a repayment. After a change is reported, review the updated eligibility results rather than assuming the change automatically permits a plan switch.

Mistake 8: Treating plan selection as the finish line

Selecting a plan on the Marketplace is not always the same thing as having active coverage. When a first premium is due, coverage generally does not begin until that payment — sometimes called the binder payment — is received by the carrier according to its instructions and deadline.

The Marketplace confirms your plan selection; the carrier effectuates the coverage once it receives payment. A household that selects a plan in December and never completes the payment step can arrive at a January appointment without active coverage. When you enroll, confirm how and when the carrier expects the first payment, complete it, and keep the confirmation.

Mistake 9: Misreading the employer-coverage rules

An offer of employer coverage can affect Marketplace financial assistance, but the result must be evaluated person by person. For the employee, affordability is generally based on the employee’s required contribution for the lowest-cost self-only plan that provides minimum value. For family members, affordability is generally evaluated using the cost of the applicable family coverage. A person offered coverage that is considered affordable and provides minimum value generally cannot receive a premium tax credit for that same period, even if the person declines the employer plan.

The Marketplace application should include complete information about the employer offer. Do not assume that the employee and every dependent receive the same eligibility result. The Marketplace makes the official financial-assistance determination from the application, and applicants should retain employer-plan information supporting the answers entered.

What these mistakes look like in Florida

Florida uses the federally facilitated Marketplace through HealthCare.gov, and plan availability varies by county — which means the networks and formularies attached to those plans vary by county too. Depending on where you live, carriers may include Florida Blue and other Marketplace insurers, each with its own directories and drug lists.

That county-level variation raises the stakes on the checking mistakes in particular: a plan comparison that was accurate for a relative in Miami-Dade may be useless in Seminole County. Our Florida ACA plans page covers what is offered across the state, and our Orlando-area health insurance page covers Central Florida specifically.

When to call a licensed Florida agent

Many of the mistakes on this list may be reduced through careful verification and follow-through, and a licensed agent can help consumers work through those checks.

A licensed agent can help review the plans available in your county, walk through the income-estimate questions, check provider directories and formularies against your household, explain how cost-sharing reductions and the metal tiers interact, and point out where the plan documents answer a question. The Marketplace and the carrier make the official eligibility and coverage determinations — an agent explains coverage; an agent does not determine it. What an agent also cannot do is guarantee a subsidy amount, an approval, or an outcome — and any agent who promises one should be treated with caution. Insurance Advisors of Florida does not charge consumers an additional fee for assistance with eligible Marketplace enrollment, and using an agent does not increase the Marketplace plan’s filed premium or reduce the premium tax credit for which a household qualifies. We are a local Florida agency with a Florida-based licensed support team. Insurance Advisors of Florida is located in Lake Mary and helps clients throughout Florida.

People also ask about Marketplace mistakes

Will I have to pay back my subsidy if my income goes up?

You may have to repay excess advance premium tax credits if actual household income or other eligibility information results in a lower final credit than the amount paid in advance. For 2026 and later tax years, the prior income-based repayment limitations no longer apply, so the full excess amount may generally be added to the household’s tax liability. Reporting changes promptly may reduce the difference.

Can I switch plans if I picked the wrong one?

During Open Enrollment, yes. Outside of it, changing plans generally requires a qualifying Special Enrollment Period, and simply regretting a plan choice is generally not a qualifying event. In limited situations — such as certain enrollment errors — the Marketplace may grant an enrollment opportunity under the applicable rules, but consumers should not assume one will be available.

Is a Bronze plan always a mistake?

No. For some households — particularly those that rarely use care and want protection against large expenses — a Bronze plan may be a reasonable fit. The mistake is choosing Bronze by premium alone, or choosing it when the household qualifies for cost-sharing reductions that are generally available only on Silver plans.

What happens if I miss the first premium payment deadline?

The carrier may not effectuate the coverage, meaning the plan selection does not become active coverage. If a payment deadline has been missed or is unclear, contact the carrier promptly — and do not assume coverage is in place until the carrier confirms it.

Do I need to re-apply every year?

Generally, you should at least update the application every year during Open Enrollment — refreshing the income estimate and household details — even if you intend to keep the same plan. Automatic re-enrollment may occur if you take no action, but it uses existing information and does not review whether the plan still fits.

Eligibility rules, premium tax credit and cost-sharing reduction amounts, plan designs, networks, formularies, and plan availability vary by household, county, and plan year, and can change. Insurance Advisors of Florida cannot guarantee eligibility, subsidy amounts, coverage, or the outcome of any Marketplace determination. This article is intended for educational purposes and is not legal or tax advice. A licensed Florida health insurance agent can review your coverage options.