Open enrollment for 2027

Open enrollment and marketplace coverage

1. Marketplace coverage: CMS Health Insurance Exchanges Monthly Effectuated Enrollment, the file with data as of May 5, 2026 (Data_asof_20260505), which runs to February 2026. Coverage in effect is what CMS calls effectuated enrollment: an active plan, with its first month's premium paid if it has one. These are national totals for February of each year, HealthCare.gov and state-run marketplaces together, all from this one file. CMS updates each month's count until the year's December data are in, so 2026 is preliminary and may change. Earlier CMS reports counted the same month sooner: its early 2025 report had 23.4 million for February 2025 (counted March 15, 2025), against 21.8 million in this file, so mixing reports would make the drop look bigger. CMS notes that Minnesota's latest data leave out a subgroup of enrollments after a reporting change; without Minnesota, the 2026 drop is 11.9%. CMS revised its 2021 counts for a new method (its early 2022 report), and its notes for this file don't say whether 2016 to 2020 were counted again the same way.
2. Plan picks: CMS's Marketplace Open Enrollment Period public use files for 2025 and 2026, the national total from the state-level file, HealthCare.gov and state-run marketplaces together. CMS counts people, not plans, including people renewed into a plan automatically. In CMS's words, "plan selections will only become coverage for consumers that effectuate their coverage by paying their first monthly premium" (public use files FAQs). The 90% and 83% divide each February's coverage by that year's plan picks. CMS's early 2025 report gave 96%, from its earlier February count.
3. Where people get coverage: FHI's tally of the U.S. Census Bureau's Current Population Survey, 2026 Annual Social and Economic Supplement, from its public-use file (asecpub26csv.zip, released September 15, 2026), for people of all ages as of their interviews from February to April 2026. Each person is counted once: anyone with Medicare under Medicare, anyone else with exactly one kind of coverage under that kind, and anyone else with two or more kinds under "more than one kind". Our tally matches the totals and margins of error Census publishes from the same survey (report P60-291, Table 1, and table H-02). Every share is within half a point either way, at 90% confidence. Medicare includes Medicare Advantage plans, which private insurers run. Job-based includes self-funded plans, where the employer pays the claims itself. Medicaid or CHIP includes other state programs for people with low incomes and Basic Health Programs, such as New York's Essential Plan. VA includes CHAMPVA, and someone with both TRICARE and VA counts under "more than one kind".
4. Why this survey: it gives marketplace plans their own category and lets us count each person once. Census's American Community Survey has no marketplace category, and Census changed its coverage question for 2025, so it warns against comparing 2025 with earlier years. Census's own published shares from this survey add up to more than 100%, since people can have more than one kind. The CDC's National Health Interview Survey is a second survey, but its latest figures are for 2025 and its marketplace figures are for people under 65, so it can't show everyone in early 2026.
5. Surveys and records: CMS's records count 19.2 million people with marketplace coverage in February 2026, 68.9 million on Medicare and 75.5 million on Medicaid or CHIP. Only surveys count job-based coverage and the uninsured. Census's survey finds fewer people with marketplace plans than CMS's records count. CMS counts plans in effect in February, the survey asks from February to April, and some coverage ends in between.
6. Medicare and Medicaid: Medicare is CMS's Medicare Monthly Enrollment count for February 2026, from the file with data through July 2026, the 50 states and DC added up; it includes Medicare Advantage. Medicaid and CHIP is February 2026's updated count for the 50 states and DC, from CMS's State Medicaid and CHIP Applications, Eligibility Determinations, and Enrollment Data (the September 2026 release). People with both Medicare and Medicaid are in both counts. Checked October 26, 2026.
7. What Denial Watch's rates cover: Denial Watch's claim denial rates are for marketplace plans in HealthCare.gov states and six states that run their own marketplace, where some figures also count plans sold outside it. Its prior authorization rates cover large Medicare Advantage plans, Medicaid plans and programs, and HealthCare.gov insurers. It has no denial rates for job-based plans or Original Medicare.
8. Plans picked, 2014 to 2026: For 2017 to 2026, the national total and its HealthCare.gov and state-run parts from CMS's Marketplace Open Enrollment Period state-level public use files, one for each year; 2025 and 2026 are the plan picks above. CMS has no file covering every marketplace before 2017, so 2014 to 2016 are from HHS ASPE's enrollment reports for 2014, 2015 and 2016, whose tables cite CMS data. Each count is of people with a plan picked, including people renewed automatically, not paid coverage, and leaves out Basic Health Program plans. The 2014 window ran from October 1, 2013 to March 31, 2014, and its count includes sign-ups through April 19, 2014. HealthCare.gov's deadline was December 15 for 2018 to 2021 and January 15 for 2022 to 2026 (January 16 for 2024); state-run marketplaces set their own deadlines. So the sign-up window was about six months for 2014, about six weeks on HealthCare.gov for 2018 to 2021, and about eleven weeks there for 2022 to 2026. For HealthCare.gov, CMS counted a picked plan for 2017 if its coverage included March and wasn't canceled, for 2018 to 2021 if any of its coverage wasn't canceled, and for 2022 on only if its coverage ran to at least January 31 (the 2017 file's definitions and CMS's 2022 public use files FAQs). CMS doesn't check state-run marketplaces' figures, and the HealthCare.gov and state-run parts shift when a state changes platform, as Georgia did for 2025 and Illinois for 2026. Checked October 25, 2026.
9. Marketplace coverage and people under 65: People under 65 are the U.S. Census Bureau's population estimates by single year of age for July 1 of the year before each February: its 2010 to 2020 intercensal estimates (nc-est2020int-agesex-res.csv) for 2015 to 2019, and its Vintage 2025 estimates (nc-est2025-agesex-res.csv) for 2020 to 2025. Where the two join, in April 2020, the newer series counts 0.07% more people under 65. Census revises every year from 2020 on with each new set of estimates; the next estimates by age are due in April 2027. No one publishes a yearly count of everyone who could buy a marketplace plan, so the chart compares coverage with everyone under 65. CMS's count is for all ages: about 1.7% of 2025's plan picks were by people 65 or older. It leaves out Basic Health Program plans, such as New York's Essential Plan; CMS's 2025 open enrollment file counts about 1.8 million people in them. February 2026 is CMS's first count for that month and may change. Checked October 26, 2026.
10. KFF: Matt McGough, Justin Lo and Cynthia Cox, "Individual Market Enrollment Continues to Fall Through Mid-2026" (KFF, October 14, 2026): plans people buy themselves, on and off the marketplaces, 25.2 million in June 2025 and 20.5 million in June 2026, from insurers' filings compiled by Mark Farrah Associates. The survey is "Cost Concerns and Coverage Changes: A Follow-Up Survey of ACA Marketplace Enrollees" (KFF, March 19, 2026): 1,117 adults who had marketplace plans in 2025, asked from February 12 to March 2, 2026, with a margin of error of plus or minus 3.8 points. Checked October 22, 2026.
11. Open enrollment: Medicare's dates from CMS's announcement (September 28, 2026) and Medicare.gov. CMS has set HealthCare.gov's 2027 sign-up dates (its statement of July 27, 2026), but the court ruling behind them is under appeal, so we link to HealthCare.gov rather than print them. Checked October 22, 2026. Oregon's move to its own marketplace is from HealthCare.gov's state page, and insurers leaving the marketplace for 2027 from KFF's tracker, checked October 19, 2026.

Back to Open enrollment for 2027