CMS proposes new eligibility-verification rules for ACA marketplaces

On 27 October 2026, the Centers for Medicare & Medicaid Services published a proposed rule in the Federal Register that would change how the Affordable Care Act's health insurance Exchanges check who is eligible to enrol and to receive premium subsidies [s1]. It is a proposal, not a final rule. Comments must be received by 27 November 2026, and the document carries the file code CMS-9873-P [s1].

This article describes what the proposal says. It does not predict whether the rule will be finalised, or in what form.

What the rule is implementing

The proposed rule says it would update Exchange eligibility and verification provisions "consistent with new requirements specified under section 71303 of Public Law 119-21 (July 4, 2025)," which CMS refers to as the Working Families Tax Cut (WFTC) legislation [s1]. In the agency's own words, the rule would affect "inconsistency periods, enrollment options during inconsistency verification procedures, annual eligibility redeterminations and eligibility redeterminations during the plan year," and would expand enrollment methods during the verification process while establishing new coverage effective dates [s1].

In plainer terms: when someone applies for marketplace coverage, the Exchange tries to confirm the facts on the application — income, household size, immigration status — against trusted electronic data sources. When the data do not line up, that gap is a "data matching issue," and the applicant enters an "inconsistency period" during which they must supply documents to resolve it [s1].

The timing mechanics the rule focuses on

Much of the proposal is about calendars that do not currently align. CMS describes a mismatch between how long an applicant has to resolve a data matching issue and how long they have to pick a plan. The agency notes that an applicant who enrols during an inconsistency period tied to their eligibility information "must verify such eligibility by the end of their 90-day inconsistency period," and that failure to do so means "their QHP enrollment through the Exchange would be terminated" [s1].

The problem CMS flags is that the 90-day window to verify can begin after the 60-day special enrolment period to actually select a plan has already closed [s1]. The agency raises the same concern about applications submitted during the annual Open Enrollment period [s1]. The proposal's adjustments to inconsistency periods, enrolment options and effective dates are aimed at that sequencing.

Why verification timing is not a small detail

The order and length of these windows determine real outcomes for applicants. A person whose documents are delayed, or who never learns that a document was requested, can be enrolled one month and terminated the next. CMS frames the exercise as a balance: it says it is seeking input on ways Exchanges can "strengthen certain verifications to promote program integrity while minimizing unnecessary or duplicative administrative burdens to the extent practicable" [s1].

The rule also touches the tax machinery behind subsidies. CMS notes that the Internal Revenue Service's updated "failure to file and reconcile" codes for the previous tax year are not available until the last week of July, which constrains how Exchanges determine advance premium tax credit eligibility for the 2028 plan year and beyond under section 36B(c)(6) of the Internal Revenue Code [s1]. That is a reminder that marketplace eligibility runs on IRS data cycles, not only on what an applicant types into a form.

How it fits the wider 2027 rulemaking

This verification proposal is one piece of a larger set of marketplace changes. CMS separately finalised the HHS Notice of Benefit and Payment Parameters for 2027 in May 2026, effective 20 July 2026, which set issuer user fees, risk-adjustment standards and plan rules for the same programme [s2]. The verification proposal would sit alongside those parameters rather than replace them.

What this article is not

This is a description of a proposed regulation and the public comment it invites. It is not advice about enrolling, and it does not forecast the rule's final content. Anyone affected would be subject to whatever version, if any, CMS ultimately finalises.

What to watch

Whether the rule is finalised after the 27 November 2026 comment deadline, and whether the final version keeps the 90-day and 60-day windows the proposal describes [s1]. Whether CMS changes the coverage effective dates, which determine when terminated or pending applicants can actually get covered. And how states running their own Exchanges adapt their systems, since the proposal reaches state-based marketplaces as well as the federal platform [s1].