Synero Open enrollment · coverage that starts in 2027
Open enrollment 2027, explained like you're 5
Medicare, the ACA Marketplace and your employer each have a window to change your health plan, and missing it can lock you in for a year. Plain-words guides to the choices, with the dates and numbers copied from official sources and where four AIs disagreed. No plan recommendations.
Key dates
- Medicare Open Enrollment
- October 15 to December 7. Changes take effect January 1, and the plan must get your request by December 7.
- Open Enrollment | Medicarechecked November 3, 2026
- Medicare Advantage Open Enrollment Period
- January 1 to March 31, for people already in a Medicare Advantage plan: one change a year, to another Advantage plan or back to Original Medicare.
- Understanding Medicare Advantage and Medicare Drug Plan Enrollment Periods | Medicarechecked November 3, 2026
- ACA Marketplace on HealthCare.gov
- Open Enrollment runs November 1 to January 15. Enroll or change plans by December 15 for coverage that starts January 1. Sign-ups from December 16 to January 15 start February 1.
- Marketplace dates and deadlines | HealthCare.govchecked November 3, 2026
- State-run marketplaces
- Some states run their own Marketplace at a different website. Check that site for its enrollment dates.
- Marketplace | HealthCare.gov glossarychecked November 3, 2026
Employer plans
Your employer sets the window, usually in the fall. Ask HR.
Pick your guide
Medicare
Original Medicare with a Medigap policy, Medicare Advantage and Part D drug plans in plain words, and what the fall window lets you change. No plan recommendations.
Four AIs: partial agreement, 76/100
Read the guideMarketplace and employer plans
ACA Marketplace plans (Bronze to Platinum, premium tax credits) and an employer's high-deductible plan with an HSA versus a PPO, with the cost math worked through. No plan recommendations.
Four AIs: partial agreement, 62/100
Read the guide
Got a plan's Summary of Benefits? Decode it.
Attach the plan's Summary of Benefits and Coverage (employer or Marketplace) or a Medicare plan's Summary of Benefits as a PDF or photo. ChatGPT, Claude, Gemini and Grok read it for what you pay, what is not covered or limited, and what to ask before you choose. A plan summary describes the plan, not you, so leave your name and member ID out.
Decode my Summary of BenefitsFree account: 3 questions, no card.
How these guides are made
For each guide, four AI models search the web and write their answers on their own. Synero combines them into one guide and grades how much they agreed. Where they disagreed, the guide shows exactly where. The dated numbers are not from the AIs: each is copied by hand from an official source, with the day it was checked.
Before you choose
This explains and does not advise. Where all four AIs agree is the solid ground. Where they disagree is exactly what to ask a licensed insurance agent, a SHIP counselor, your employer's HR or benefits team, or a tax professional. Guides updated November 3, 2026.