The ACA Open Enrollment Period closes on January 15 in most states that use the federal HealthCare.gov platform, with some state-based Marketplaces setting different deadlines. If you missed the deadline and are now uninsured, you are not necessarily locked out of health coverage for the remainder of the year -- but your options depend on your specific circumstances, and some alternatives come with significant limitations.
Check Whether You Qualify for a Special Enrollment Period
The first thing to determine is whether you have experienced -- or are about to experience -- a qualifying life event that triggers a Special Enrollment Period (SEP). SEPs allow enrollment in ACA Marketplace coverage outside the standard Open Enrollment window. Common qualifying events include:
- Losing job-based health coverage (including COBRA expiration)
- Getting married or divorced
- Having or adopting a child
- Permanently moving to a new coverage area
- Losing Medicaid or CHIP eligibility
- A change in household income that affects premium tax credit eligibility (under 2026 rule expansions)
If any of these apply, you typically have 60 days from the qualifying event to enroll through HealthCare.gov or your state Marketplace. Documentation of the event is required. If you are approaching a qualifying event -- a job change, a move, a marriage -- the SEP clock starts from the event date, so plan accordingly.
Check Medicaid and CHIP Eligibility
Medicaid and the Children's Health Insurance Program (CHIP) have no enrollment deadlines. If your household income falls within your state's eligibility thresholds, you can apply and receive coverage at any point during the year. In states that have expanded Medicaid under the ACA, adults with incomes up to 138% of the federal poverty level are eligible. Children and pregnant women may qualify at higher income levels under CHIP.
Eligibility thresholds and application processes vary by state. HealthCare.gov will screen your application for Medicaid eligibility and route you to your state's program if you qualify. Medicaid coverage, if approved, is typically effective the month of application or the month following, with no gap in coverage for approved applicants.
Short-Term Health Plans: A Limited Option
Short-term limited-duration health insurance plans are available year-round without an enrollment window. These plans are not subject to ACA requirements -- they can deny coverage based on pre-existing conditions, exclude certain benefits, and cap total payouts. Federal rules currently limit short-term plans to initial terms of three months, with renewals possible up to a total of four months in most states, though some states impose shorter limits or prohibit short-term plans entirely.
Short-term plans are best understood as a temporary bridge for healthy individuals facing a brief gap in coverage -- not a substitute for ACA-compliant insurance for anyone with ongoing medical needs, prescription requirements, or expected healthcare utilization. Premiums are typically lower than ACA plans, but that comparison is not meaningful if the short-term plan excludes conditions you actually have or caps benefits well below what you might need.
Employer Coverage Outside Open Enrollment
If you are newly eligible for employer-sponsored health insurance -- because you started a new job, reached the end of a waiting period, or experienced a qualifying event -- your employer's plan enrollment window is separate from the ACA Marketplace Open Enrollment Period. New hire enrollment typically opens upon hire or at the end of a waiting period (no more than 90 days under ACA rules) and is not affected by Marketplace deadlines.
Going Without Coverage: Understanding the Risk
The federal individual mandate penalty was reduced to zero starting in 2019, so there is no federal tax penalty for being uninsured. Some states -- California, Massachusetts, New Jersey, Rhode Island, Vermont, and Washington D.C. -- maintain their own individual mandate requirements with associated penalties.
The financial risk of being uninsured is the primary concern. A single emergency room visit can cost several thousand dollars; a hospitalization or surgical procedure can quickly reach tens of thousands. For most people, the premium cost of maintaining coverage -- particularly with ACA premium tax credits that have been enhanced through 2025 -- is far lower than the financial exposure of a single significant medical event while uninsured.
Use our Health Insurance Calculator to estimate your coverage costs and subsidy eligibility, and see our ACA Subsidies guide for a full breakdown of premium tax credit eligibility.