ACA Pre-Eligibility Verification: What Changes for 2028

A proposed CMS rule published October 27, 2026 would stop Exchanges from paying a premium tax credit or cost-sharing reduction to anyone whose income, citizenship, residency, or other-coverage information can’t be verified — and it would make every enrollee come back once a year, starting August 1, 2027, to confirm that information again before the next plan year. Nothing changes for 2027 plan year applications. The first plan year this touches is 2028, and the rule is still a proposal with an open comment period. But the clock that matters to you starts now, because the manual chase this creates — tracking which clients have an unresolved data matching issue and which deadline they’re up against — isn’t new. CMS already runs a version of it, and this proposed rule makes it bigger, annual, and tied directly to whether your client’s subsidy keeps flowing.

What CMS actually proposed

CMS’s proposed rule, filed under CMS-9873-P and RIN 0938-AW03, amends 45 CFR Part 155 to implement new verification requirements the agency says come from “section 71303 of Pub. L. 119-21 (July 4, 2025), which we refer to as the Working Families Tax Cut (WFTC) legislation” (CMS, proposed rule CMS-9873-P, Federal Register document 2026-21891). That’s the same public law the IRS calls the One, Big, Beautiful Bill Act in its own parallel rulemaking on the premium tax credit — two agencies, two separate proposed rules, one underlying statute. We covered the IRS side of that statute, including the repayment cap change, in our piece on the ACA premium tax credit repayment cap; this article is about the CMS/Exchange operational side of the same requirement.

The core mechanism is a change to how Exchanges handle what CMS calls a data matching issue, or DMI — the agency’s term for when information on a Marketplace application doesn’t match what a trusted data source (the IRS, Social Security, DHS, and others) shows on file. Today, an applicant with a DMI generally still gets APTC and CSRs while the issue is open, during what CMS calls an “inconsistency period,” as long as they’re otherwise eligible based on what they put on the application. The proposed rule would end that for five specific categories. CMS proposes to amend 45 CFR 155.315(f)(4)(ii) so that Exchanges “would not be able to authorize payment for advance payments of the premium tax credit (APTC) and cost-sharing reductions (CSRs) for applicants who have data matching issues (DMIs)” in these areas, until the DMI is resolved — unless the household qualifies for a special enrollment period under 45 CFR 155.420(d)(2)(i) or (ii) (CMS, proposed rule CMS-9873-P):

That 90-day-general, 95-day-citizenship split isn’t new; it’s the existing inconsistency-period rule CMS describes in the proposed rule’s own background section, tracing back to how the agency interpreted section 1411(e) of the Affordable Care Act in the 2012 Exchange Establishment Rule (CMS, proposed rule CMS-9873-P, Section II.A). What’s new is tying the outcome of that period directly to whether APTC and CSRs flow at all for those five categories, instead of letting the applicant receive assistance during the window while the issue gets sorted out.

The legal chain: one sentence in a 2025 tax law becomes a 2028 verification rule

Section 71303(a) of the WFTC legislation adds new paragraph 36B(c)(5) to the Internal Revenue Code, effective for tax years beginning after December 31, 2027. Starting January 1, 2028, a month generally isn’t a “coverage month” for premium tax credit purposes unless an Exchange “verifies,” using “applicable enrollment information that shall be provided or verified by the applicant,” the enrollee’s eligibility to enroll in a qualified health plan and, where relevant, for APTC for that month (CMS, proposed rule CMS-9873-P, Section II.A, citing 26 U.S.C. 36B(c)(5)(A)). The statute spells out exactly what “applicable enrollment information” means: household income and family size, whether the enrollee is an eligible alien, health coverage status or eligibility, place of residence, and anything else Treasury and HHS determine necessary. Two built-in protections are worth knowing: a consumer can’t be found ineligible to enroll solely for failing to meet this verification requirement for a given month, and Treasury can waive the requirement for someone enrolling through a special enrollment period tied to a change in family size — a newborn, an adoption, a marriage.

Section 71303(b) adds a second lever. It amends the Code’s definition of a qualified health plan, for purposes of the premium tax credit, to exclude any plan “enrolled in through an Exchange that does not provide a process through which any consumer may verify their household income and eligibility for QHP enrollment for the following plan year.” That process has to be in place no later than August 1, 2027, and by August 1 of every year after that, for current enrollees seeking APTC for plan year 2028 and beyond to stay eligible (CMS, proposed rule CMS-9873-P, Section II.A). That’s the statutory root of the pre-Open Enrollment verification window covered next — it isn’t a CMS invention, it’s CMS building the Exchange-side plumbing the 2025 tax law already requires.

The new verification calendar

CMS’s proposed rule translates that statute into a specific annual sequence. The centerpiece is a new section, proposed 45 CFR 155.410(h), requiring every Exchange to run a pre-Open Enrollment (pre-OE) verification period each year, starting August 1 and continuing until that Exchange’s Open Enrollment Period begins, during which enrollees can provide eligibility information for the coming plan year and the Exchange has to attempt to verify it (CMS, proposed rule CMS-9873-P). A second, related change, to 45 CFR 155.335, governs what happens to someone who’s already enrolled: CMS proposes that an Exchange may not redetermine an enrollee eligible for APTC and CSRs for the next plan year unless the enrollee or their application filer provides or confirms household income and family size, citizenship or eligible noncitizen status, eligibility for other coverage, and place of residence — and that confirmation has to land on or after August 1 and no later than December 31 of the year before the plan year it covers.

CMS proposes new effective-date rules alongside this, too. If a consumer “pends” a plan selection during Open Enrollment or an SEP while a DMI resolves, and CMS resolves all of a consumer’s relevant DMIs by the 15th of the month following their originally scheduled coverage date, they keep that original effective date. Resolve it later in that same month, and the effective date becomes the first of the month of resolution. Resolve it after that, and it pushes to the first of the following month (proposed 45 CFR 155.410(f)(5), 155.420(b)(6)). CMS is also proposing a new section, 155.400(i), requiring Exchanges to let applicants and enrollees pend a plan selection so coverage only becomes effective once APTC and CSR eligibility is actually determined — which keeps a client from getting billed full price for a plan they technically selected before their subsidy was confirmed.

Why this happens: the mechanism behind a data matching issue

A DMI isn’t a judgment call by a caseworker. It’s what happens when the number or status a consumer puts on a Marketplace application doesn’t match what an automated check against a trusted data source returns — the IRS for income, the Social Security Administration or DHS for citizenship and immigration status, a state Medicaid agency for other coverage. CMS describes the mechanism plainly: “Exchanges check trusted data sources to determine if application information is reasonably compatible with information from those data sources. In cases where the information is not reasonably compatible or data is unavailable, generally the applicant will receive notification of a data matching issue” (CMS, proposed rule CMS-9873-P, Section II.A). The applicant then has the 90-or-95-day inconsistency period to submit documentation and resolve it.

Agents already deal with a cousin of this process: periodic data matching, or PDM. It’s an existing, separate check CMS runs twice a year on everyone currently enrolled with financial assistance, looking only at dual enrollment in Medicare or Medicaid/CHIP and at death — not income, citizenship, or residency. CMS’s own guide for agents and brokers, updated June 2026, lays it out: “If consumers do not take action when they receive a PDM notice, the Marketplace will end financial assistance or coverage after 30 days” (CMS, Agents and Brokers Guide to Marketplace Periodic Data Matching, updated June 2026). That 30-day scramble, twice a year, for a narrow set of checks, is the version of this problem agents already know. The pre-eligibility verification proposed rule is the same basic shape — an automated check, a notice, a clock, a consequence for silence — applied to five broader categories, run annually instead of twice yearly, and tied to whether the subsidy itself keeps flowing rather than just to Medicare/Medicaid dual enrollment.

What it costs when this goes unresolved

The dollar stakes here aren’t abstract. CMS’s own Plan Year 2026 fact sheet says tax credits are “projected to cover 91% of the lowest cost plan premium in 2026 for eligible enrollees,” with the average Marketplace premium after tax credits projected at $50 per month for that lowest-cost plan (CMS, Fact Sheet, Plan Year 2026 Marketplace Plans and Prices, October 30, 2025). If a client’s DMI goes unresolved in one of the five categories this rule covers, that 91% coverage doesn’t shrink — it disappears for that household until the issue clears. A client paying roughly $50 a month is suddenly paying close to the full premium, not a reduced one, for every month the DMI sits open.

CMS has also shown it will act on exactly this kind of verification failure at scale. In the same March 2026 press release reporting 23.1 million total 2026 Marketplace enrollees, the agency said it “ended advance payment of the premium tax credit (APTC) or coverage for nearly 1.5 million people” found to be ineligible for financial assistance or enrolled without authorization on HealthCare.gov during 2025 (CMS, Press Release, Exchange Coverage Remains Near Record High as 23.1 Million Enroll for 2026, March 27, 2026). The same release notes that 46% of 2026 enrollees had household incomes between 100 and 150% of the federal poverty level, “with the vast majority receiving financial assistance” — exactly the income band where a 90-day income DMI, or a full year without a subsidy, lands hardest.

Put those together and the shape of the risk is clear: CMS is already enforcing verification aggressively on the existing rules, enrollment is concentrated in income bands where the subsidy is most of the premium, and this proposed rule adds a fifth category (residency) and an annual, calendar-driven recheck on top of what’s enforced today. Results may vary by household and by how quickly a DMI gets resolved, but the direction isn’t in question.

The manual method: how to keep a client’s subsidy from lapsing

None of this requires a tool. It requires a calendar and a habit, and it’s the same discipline whether the rule finalizes as proposed or changes first.

Everything above works whether you join anything or not. Run it on your current ACA book this week — most agents have at least a few clients sitting on an open DMI they haven’t flagged yet.

How Ambrose handles the chasing

The manual method above is a discipline. Where Ambrose actually helps is turning “check every client’s DMI status by hand, on a date you have to remember” into a scheduled job that runs itself and tells you what needs attention.

Ambrose’s data layer, the Brain, currently documents 33 federal and health data sources and 205 live tools, confirmed on Ambrose’s own “What is Ambrose?” page as of this writing, with its stated operating rule being “never invent a number” (Ambrose docs, What is Ambrose?). The piece that fits this specific problem is a Routine: documented as “a scheduled prompt attached to an agent or a team,” set on a standard five-field cron schedule, with an optional output destination of Slack, email, a GHL note, or log only (Ambrose docs, Routines). Point a routine at an agent with access to client-vault — documented as the “client-facing enrollment + policy store” spoke — and write the prompt to pull every ACA client’s DMI deadline and flag anyone whose window closes inside the next 15 days (Ambrose docs, Spokes overview). Schedule it daily, point the output at Slack, and the list that used to require opening every client’s HealthCare.gov account by hand shows up in the channel your team already reads.

Being precise about what that is and isn’t: the filtering logic — “15 days before deadline,” “unresolved DMI only,” whatever rule you want — lives in the prompt you write for the routine, not in a built-in DMI-tracking button. Ambrose doesn’t currently document a purpose-built “DMI tracker” feature; what it documents is a general scheduling and prompt framework flexible enough to build one yourself, reading from the agency’s own book of business in client-vault. That’s a real difference from a packaged compliance tool, and it’s worth saying plainly instead of implying otherwise. What it buys you is the same question — “which of my clients needs a document chased down before a deadline” — answered on a schedule instead of only when you remember to ask it.

What’s still just a proposal, and how to comment

It’s worth repeating because it’s easy to lose in a rule this detailed: none of this is final, and none of it changes 2027 plan year enrollment. CMS Administrator Dr. Mehmet Oz framed the agency’s reasoning plainly in the press release announcing the proposal: “Federal subsidies should only go to eligible Americans, not to fraudsters gaming the system.” Treasury Secretary Scott Bessent added that the changes close “eligibility loopholes” so premium tax credits “go to eligible Americans” (CMS, Press Release, October 23, 2026). CMS is genuinely asking for input in a few specific places: how to strengthen residency verification without relying primarily on self-attestation, how to strengthen family size verification, and whether consumers who apply for Medicaid or CHIP during the new pre-OE window should also qualify for the existing Medicaid-denial special enrollment period.

Compliance: what this article covers, and what it doesn’t

Nothing in this article is insurance, legal, or tax advice. CMS-9873-P is a proposed rule, published October 27, 2026, and CMS can finalize it with changes, delay it, or decline to finalize it after reviewing comments. Every CFR citation and date here reflects the proposed text as filed; confirm the current status of any provision with CMS directly before advising a client, since a proposed rule is not enforceable law. This article covers the ACA Marketplace side of verification; it doesn’t touch Medicare Advantage or Part D marketing rules, which carry their own TPMO disclaimer and CMS marketing requirements covered in our guide to Medicare sales call scripts for 2027. If you use AI tools to help manage client outreach around this rule, keep Social Security numbers, immigration documents, and income figures out of any tool without a signed Business Associate Agreement — see the NAIC AI Model Bulletin guidance linked above for what a written policy should cover.

The close

This proposed rule doesn’t change anything you’re doing today. What it does is put a hard date — August 1, 2027 — on a habit every ACA agent should already have: knowing which clients have an open data matching issue and which deadline they’re racing. Build that habit now, on the existing 90/95-day inconsistency periods, and the annual version this rule adds in 2027 is just a bigger version of a list you already keep. Run the manual method above on your book this week. If you’d rather have that list generated for you on a schedule, with someone who’s already built the routine walking you through it, one Ambrose seat comes with a Tech Savvy membership.

Related reading: our breakdown of the IRS side of this same verification requirement and the repayment cap, the 400% FPL subsidy cliff income check, how to re-shop your ACA book before Open Enrollment, and what happens to an ACA subsidy when a client turns 65.