The 2027 ACA Marketplace open enrollment period opens November 1, 2026 and closes January 15, 2027 on HealthCare.gov. That is 76 days. Most agencies writing a meaningful volume of Marketplace enrollments will tell you those 76 days feel like about 40 once you account for the Medicare AEP overlap, the November 15 hard deadline for January 1 starts, and the clients who call on January 14.
Key Takeaways
- The 2027 ACA open enrollment period on HealthCare.gov (FFM) runs November 1, 2026 through January 15, 2027. This window applies to all 34 states that use the federal platform.
- November 15 is the cut-off for January 1, 2027 coverage starts. Clients who enroll between November 16 and December 15 get February 1 coverage. Clients who enroll between December 16 and January 15 get March 1 coverage.
- State-based exchanges set their own closing dates. California Covered California, New York NY State of Health, and DC Health Link typically extend to January 31. Verify dates with each SBE in September before publishing client-facing materials.
- Medicare AEP runs October 15 through December 7, 2026. Agencies handling both Medicare Advantage and Marketplace enrollments face peak staffing pressure for 53 days during those overlapping windows.
- Clients who experience a qualifying life event outside OEP can enroll any time during their 60-day SEP window. The OEP calendar does not affect SEP eligibility.
FFM and SBE dates for 2027 coverage
HealthCare.gov governs 34 states. The 17 state-based exchanges set their own timelines, and several extend past January 15. Before building any client-facing outreach calendar for OEP 2026, confirm the closing date for every state where your agency writes business directly from the exchange website. The dates below are based on historical patterns and current CMS guidance; SBE states can adjust their windows.
| State / Platform | Exchange | Opens | Closes | Notes |
|---|---|---|---|---|
| HealthCare.gov (34 FFM states) | Federal Marketplace | November 1, 2026 | January 15, 2027 | Nov 15 for Jan 1 start. Dec 15 for Feb 1 start. |
| California | Covered California | November 1, 2026 | January 31, 2027 (expected) | CA historically extends to Jan 31. Confirm at coveredca.com. |
| New York | NY State of Health | November 1, 2026 | January 31, 2027 (expected) | NY has matched CA on the Jan 31 extension in recent years. |
| Massachusetts | Commonwealth Connector | November 1, 2026 | January 23, 2027 (expected) | MA deadline typically falls in the third week of January. |
Dates based on historical patterns and current CMS guidance. SBE states set their own timelines. Confirm each exchange website in September 2026 before publishing client communications.
The November 15 deadline most clients miss
On HealthCare.gov, the OEP window runs through January 15, 2027. Most clients hear "open enrollment ends January 15" and assume they have until mid-January to make a decision. The date that actually matters for most of your clients is November 15.
Under the FFM coverage effective date rules, enrollments completed by November 15 receive January 1 coverage. Enrollments completed between November 16 and December 15 receive February 1 coverage. Enrollments completed between December 16 and January 15 receive March 1 coverage. A client who decides on December 20 that they want coverage as soon as possible will have a gap in January and February before their March 1 plan takes effect.
For clients who need January 1 coverage, November 15 is not a soft preference. It is the hard cutoff. Brokers who do not communicate this clearly by the end of October will spend early December fielding calls from clients who thought they had more time. For the full coverage effective date framework, including SEP start dates, read ACA coverage effective date rules.
The Medicare AEP overlap
Medicare AEP runs October 15 through December 7, 2026. ACA Marketplace OEP opens November 1, 2026. The overlap period from November 1 through December 7 is 37 days. For agencies that serve both Medicare-eligible and under-65 clients, those 37 days will be the busiest stretch of the year.
The practical problem: a 64-year-old client turning 65 in February 2027 needs a Medicare Initial Enrollment Period conversation in the fall, not a Marketplace renewal. Routing the wrong client into the wrong track wastes time on both ends and can result in late enrollment penalties if Medicare Part B is missed. For the Medicare to Marketplace transition rules, see ACA Marketplace and Medicare coordination.
Agency prep timeline: July through January
The agencies that close AEP cleanly are not the ones who start early in November. They are the ones who started in July. A book audit, an income sweep, and a carrier change review done in August leave three months to prepare outreach before OEP opens. The timeline below maps the recommended sequence.
July / August
- Audit the current book for clients whose income changed more than 10 percent. APTC is based on projected income; a mid-year change that was not reported creates repayment risk on Form 8962.
- Flag clients who are aging into Medicare (turning 65 before July 1, 2027). They need a Medicare IEP counseling call before November.
- Pull a list of any clients whose carrier is exiting markets or restructuring networks. Carrier announcements typically come in late summer.
- Run a preliminary look at 2027 plan data as it becomes available from CMS, typically in late September.
September / October
- Confirm SBE closing dates for every state where you write business. Do not assume dates match HealthCare.gov.
- Build your outreach sequence: email 1 in October, follow-up call in early November, confirmation email by November 12 for January 1 start.
- Check for Medicare AEP conflicts if your agency handles both. October 15 through December 7 overlaps the first 37 days of Marketplace OEP.
- Pre-populate clients in your quoting tool. Running APTC estimates before the first client conversation saves 8 to 12 minutes per call.
November 1 to November 15
- Prioritize active clients first. The November 1 to 15 window is the only period where every enrollment guarantees a January 1 start.
- Document each enrollment confirmation with the plan ID, coverage start date, and APTC applied. Discrepancies from the 1095-A that arrives in January need a paper trail.
- Watch for carrier technical issues in the first two weeks of OEP. HealthCare.gov volume is highest in this window.
November 16 to January 15
- Continue working through the book on clients who could not be reached in the first window.
- Remind clients that February 1 coverage starts require enrollment by December 15.
- For clients who do not respond before January 15, confirm whether auto-renewal is in place and whether the crosswalked plan is acceptable.
Auto-renewal is not a plan for OEP
CMS allows clients who do not actively re-enroll to auto-renew into their current plan or a crosswalked plan at the prior year's income projection. For a book that was well-managed all year, auto-renewal catches some clients. For the majority, it results in clients who end up in a plan that no longer matches their needs or income, with APTC calculated on last year's projection.
The auto-renewal problem compounds when carriers restructure their network or exit a market. CMS crosswalks clients to a similar plan from the same carrier when possible, but crosswalked plans can have different networks, drug formularies, and cost-sharing structures. A client who auto-renewed because their broker did not reach them in November may discover in February that their primary care doctor is no longer in-network. For the full auto-renewal risk picture, read ACA auto-renewal risks.
FAQ
Questions brokers ask about ACA open enrollment timing.
What is the difference between AEP and OEP for ACA brokers?
AEP (Annual Enrollment Period) refers specifically to Medicare plan selection and runs October 15 through December 7, 2026. OEP (Open Enrollment Period) for ACA Marketplace plans runs November 1 through January 15, 2027 on HealthCare.gov. The terms are often used loosely in the industry, which creates confusion for clients. When a broker says they are in AEP, they may be handling Medicare enrollments, Marketplace enrollments, or both. Agencies that serve dual-eligible or near-Medicare-age clients need separate staffing plans for the overlapping weeks.
If a client misses the January 15 deadline, what are their options?
A client who misses the OEP deadline without a qualifying life event cannot enroll until the next OEP unless a Special Enrollment Period trigger occurs. Qualifying events that open a 60-day SEP include: loss of other coverage (job loss, COBRA expiration, Medicaid termination), change in household size (birth, marriage, adoption), change in residence (new county or ZIP code with different plan options), and a few others. A client who simply forgot to enroll does not have a qualifying event. They remain uninsured until the following November 1 unless something in their life changes their coverage situation.
Do SBE state deadlines also shift the coverage start dates?
Yes, each SBE determines both its closing date and its coverage start date rules, which may differ from the FFM. California Covered California, for example, has historically offered a January 1 coverage start for enrollments completed by December 15, similar to the FFM, but with a later overall OEP closing date. The coverage effective date tied to specific enrollment windows is set by each exchange. Brokers writing business in SBE states should pull the coverage effective date schedule from each exchange website in October before advising clients on timing.
Can a client enrolled in COBRA also enroll during OEP?
Yes. A client currently enrolled in COBRA can enroll in a Marketplace plan during OEP and drop COBRA effective the new Marketplace plan's coverage start date. COBRA enrollment does not constitute other minimum essential coverage that blocks Marketplace enrollment. However, APTC eligibility while enrolled in COBRA is a separate question: a client who is actually enrolled in COBRA (not just eligible for COBRA) is considered to have other coverage available and cannot claim APTC for the months of COBRA enrollment. The practical advice: time the COBRA termination to align with the Marketplace start date.
How far in advance should brokers contact clients about OEP?
A first outreach in October, before OEP opens on November 1, puts brokers in the best position. Clients contacted before November 1 arrive at the enrollment conversation having already thought about their coverage. A second touch in the first two weeks of November targets the November 15 deadline for January 1 starts. Agencies using Quotit, Connecture, or similar platforms to manage their books typically export client lists in September and segment by priority: clients with income changes, clients whose carriers are restructuring, clients approaching Medicare eligibility, and clients who went through a life event during the year. QualityQuotes allows brokers to run plan comparisons with live CMS data and APTC applied before the first client call.
