ACA Insurer Leaving in 2027? Don't Let HealthCare.gov Pick

Denise is 57, does freelance bookkeeping in Fort Worth, and pays $352 a month for a Cigna silver plan she chose because her endocrinologist was in it. In mid-October a letter told her Cigna is leaving the Texas ACA marketplace on December 31, 2026. She read it twice, tucked it under the electric bill, and figured HealthCare.gov would sort it out. (Denise is a composite, but a few hundred thousand people got some version of her letter this fall.)

HealthCare.gov will sort it out, in a way. If she does nothing by December 15, the marketplace will put her in a plan from a different insurer for 2027, one chosen by a formula that never asks about her endocrinologist. Open enrollment for 2027 coverage starts today, November 1. If your insurer is on this year's exit list, auto-renew stops being a safe default, and the next six weeks are when you get to choose for yourself.

Who's leaving the marketplace for 2027

The list is long this year. Becker's Payer Issues keeps a running tally, last updated October 6, 2026, that counts a dozen insurers pulling out of all or part of the ACA exchanges after this year.

Cigna is the biggest. It's leaving the exchanges in 11 states (Arizona, Colorado, Florida, Georgia, Illinois, Indiana, Mississippi, North Carolina, Tennessee, Texas and Virginia), a move Becker's says affects about 369,000 members. Baylor Scott & White Health Plan is leaving the Texas exchange too, which touches roughly 100,000 people, or about 2.6% of the state's marketplace. Molina is shrinking from 14 states to six. Medica is out of Iowa, Kansas and Oklahoma. UnitedHealthcare is leaving Georgia, Centene's Ambetter is leaving Delaware and New Hampshire, CareSource is leaving Indiana, Ohio and West Virginia, and PacificSource is pulling out of Oregon, Idaho and Montana. ConnectiCare will sell only off the exchange in Connecticut, where subsidies don't apply.

Even if your insurer is staying, your 2027 numbers will look different. KFF's review of rate filings from 276 insurers, updated August 3, 2026, found a median proposed premium increase of 15% for 2027. That follows a median finalized increase of 20% for 2026, so this is the second double-digit year in a row.

What auto-renew does when your insurer leaves

HealthCare.gov spells it out on its automatic re-enrollment page: "If your company isn't offering any similar plans for the next year, we'll re-enroll you in a comparable one with a different insurance company."

"Comparable" is carrying a lot of weight in that sentence. Under federal rules in place since 2017, as health policy writer Louise Norris explains at healthinsurance.org, the federal exchange tries to move you into the lowest-premium plan at the same metal level with the same network type. So a silver HMO enrollee lands in the cheapest silver HMO another insurer sells in her area.

The formula checks metal level, network type and price. It doesn't check whether your doctors are in the new network, whether your prescriptions are on the new formulary, or which hospital system the plan uses. Two silver HMOs can be built around completely different hospitals.

One more wrinkle: not every state auto-places people at all. Healthinsurance.org notes that Cigna enrollees in Colorado, which runs its own exchange, won't be automatically placed in a new plan when their coverage ends on December 31. In a state like that, doing nothing means starting 2027 uninsured. If you use a state-run exchange, read your letter closely for what happens if you don't act.

Run the numbers the way Denise should

Your premium tax credit is a dollar figure, and it's the same no matter which plan you pick. The marketplace takes the price of the benchmark plan (the second-lowest-cost silver plan in your area) and subtracts what the IRS says you should contribute based on your income. For 2027, IRS Revenue Procedure 2026-26 sets that contribution on a sliding scale from 2.15% of income at the low end up to 10.22% for people between 300% and 400% of the poverty line.

Denise expects to earn $46,000 in 2027. With the poverty line at $15,960 for a single person in the guidelines used for 2027 coverage, she's at about 288% of poverty. That puts her expected contribution at roughly 9.85% of her income, or about $378 a month. Say the benchmark silver plan for a 57-year-old in her county costs $1,080 a month (a made-up figure for illustration). Her credit works out to about $702 a month, and she can put it toward any bronze, silver, gold or platinum plan on the exchange.

At first glance the auto-renew pick looks like a win. At $308 a month, it's cheaper than the $352 she pays now. Keeping her doctor costs $180 more a month, or $2,160 for the year.

That might be money well spent, or it might not. If she sees the endocrinologist four times a year and has a long history with him, the PPO could easily be worth it. If she'd be fine with a new specialist in the HMO's network, the cheaper plan saves real money. The point is that she should make that trade on purpose. An HMO generally won't pay anything for non-emergency out-of-network care, and the federal out-of-pocket maximum, which rises to $12,000 for 2027 from $10,600 this year according to healthinsurance.org, only protects you for in-network care.

The second trap: last year's income on your application

Auto-renew also carries your old application forward. HealthCare.gov's own advice is to log in and "update your application with your expected income and household information" before the deadline.

That matters more than it used to. The One Big Beautiful Bill Act (Section 71305) eliminated the caps on repaying excess advance premium tax credits, starting with 2026 coverage, according to healthinsurance.org. Every dollar of extra subsidy now comes back at tax time.

Say Denise's file still shows $38,000 from a slow year and she earns $46,000 in 2027. At $38,000, the marketplace would figure her credit at about $820 a month instead of the $702 she qualifies for. The extra $118 a month adds up to about $1,411 she'd owe back when she files her 2027 return in spring 2028. A really good year is worse. Above 400% of poverty ($63,840 for a single person for 2027 coverage), you don't qualify for any credit, so whatever the marketplace paid on your behalf all comes back.

It cuts the other way too. If your income dropped, an auto-renewed application based on a better year can leave you paying more each month than you need to until you update it.

The dates that matter this year

You may have heard open enrollment was getting shorter. A 2025 federal rule would have ended HealthCare.gov's window on December 15 this year, but according to healthinsurance.org it never took effect, and CMS confirmed in August that the window runs November 1, 2026, through January 15, 2027.

Pick a plan by December 15 and it starts January 1. Pick between December 16 and January 15 and it starts February 1. If you were auto-renewed and your coverage has already kicked in, HealthCare.gov says you can still switch plans until January 15.

State-run exchanges set their own calendars. California, New Jersey, New York and the District of Columbia run through January 31, while Idaho closes December 15, per healthinsurance.org's state list. Check yours.

Losing your insurer also opens a special enrollment period. Healthinsurance.org says it starts 60 days before your plan ends and runs 60 days after. The window helps if you miss a deadline, but a plan you pick after December 31 generally starts on the first of the following month, so I wouldn't plan around it.

How to shop the replacement

I'd start with your doctors and prescriptions, since the auto-renew formula ignores both. Write down every doctor you see regularly, the hospital you'd want to go to, and every prescription with its dose. HealthCare.gov's plan comparison lets you add doctors and drugs and filter plans by them. Then call your doctors' billing offices and ask whether they'll be in network for the specific 2027 plan you're considering. Directories are often wrong, and new contracts for next year sometimes aren't finalized when the directories go up.

Next, compare full annual cost rather than monthly premium. Multiply the premium by 12, then add a realistic guess at what you'd spend before hitting the deductible. A plan that's $50 cheaper a month but has a $3,000 higher deductible isn't cheaper for someone who uses care.

If your income is at or below 250% of poverty ($39,900 for a single person), look hard at silver. Silver plans come with cost-sharing reductions at those incomes, which lower your deductible and copays, and those extra savings only come with silver. If you're healthy and your income is higher, every bronze and catastrophic marketplace plan remains HSA-eligible in 2027, and the HSA contribution limit rises to $4,500 for self-only coverage, according to healthinsurance.org. HSA contributions also lower the income the marketplace uses, which helps if you're near the cliff.

Finally, if your departing insurer offers to keep you through an off-exchange plan, remember you can't use your premium tax credit there. For most subsidized enrollees, that ends the conversation.

Bottom Line

Here's what to do this week if your insurer is leaving the marketplace:

1. Find the letter and confirm the end date, which for most people is December 31, 2026. If you're on a state-run exchange, find out whether you'll be automatically placed in a new plan or simply dropped.
2. Log in to HealthCare.gov or your state exchange and update your 2027 income and household. With the repayment caps gone, a stale estimate can turn into a four-figure tax bill in 2028.
3. List your doctors, hospital and prescriptions, then compare at least three plans by full annual cost: the auto-renew pick, the benchmark silver, and the plan that keeps your doctors.
4. Choose and enroll by December 15 so your new plan starts January 1. Put a reminder on December 10 so you aren't racing the deadline.

Denise did the math at her kitchen table and decided her endocrinologist was worth $180 a month. You might land somewhere else, and the cheap plan could be the right call for you. Just make sure you're the one who picked it.