GLP-1 Formulary Changes: The 2025–2026 U.S. Tracker

The finding

GLP-1 formulary and coverage changes are not uniform across payer type, drug, presentation, or indication — and the same effective date can mean very different things depending on the plan.

Of the 16 verified events in this tracker spanning January 2025 through October 2026, nine narrowed access for at least one group of members, four broadened access through new pathways or lifted limits, one maintained access through a product substitution, and two were mixed — expanding access for one presentation while contracting it for another.

Seven of the 16 events carry an effective date other than January 1, including changes dated June 1, July 1, October 1, and December 12. The assumption that formulary changes only happen at the start of a plan year is wrong.

The same drug — Zepbound — appears in events where it was excluded, then named preferred with a presentation carve-out, and then scheduled to return as preferred at a second PBM the following October. Access to a drug depends on which presentation, which formulary, and which plan sponsor's document is in effect at the time of dispensing.

Key terms used in this tracker

Precision matters. The following definitions are used consistently across every row in the tracker to prevent misrepresentation.

Source: WPG Research Team definitions, July 2026.

Full tracker: 16 verified events

Sorted by effective date. Each row is one formulary or coverage action by one organization. Events covering multiple plan options at the same organization are listed as a single row with the scope noted. All sources are primary plan, program, or PBM documents.

Source: WPG Research Team manual review of primary plan, PBM, and program documents. Last verified July 31, 2026. See individual source links above for primary documentation.

PBM formulary changes (2 events + 1 carrier)

The two largest commercial PBMs — Express Scripts and CVS Caremark — made competing and partially inverse decisions about Zepbound during the period covered by this tracker. A third carrier-level action by Blue Cross Blue Shield of Michigan added an indication exclusion for fully insured employer clients.

Express Scripts National Preferred Formulary — July 1, 2026 (F14)

Express Scripts revised its National Preferred Formulary (NPF) effective July 1, 2026 to list Zepbound single-dose pens as preferred alternatives, while excluding Zepbound KwikPens and Zepbound vials. The revision creates a presentation-level split: Zepbound the molecule is accessible, but only one of its delivery formats remains on the preferred list.

Express Scripts explicitly states in its NPF communications that member benefit materials control because not every plan covers every drug listed on the NPF. An employer that contracts with Express Scripts but uses a custom formulary may have different Zepbound coverage than the NPF template specifies.

CVS Health commercial template formularies — October 1, 2026 (F16)

CVS Health announced that Zepbound will return to its most common commercial template formularies as an additional preferred option effective October 1, 2026. The announcement does not specify which Zepbound presentation (pen, KwikPen, or vial) will be included, and plan sponsors retain discretion to customize their formulary from the CVS template.

Members with CVS Caremark coverage should not assume the October 1 change applies to their plan without confirming with their plan sponsor or through their benefit summary.

BCBS Michigan / Blue Care Network — January 1, 2025 (F01)

Blue Cross Blue Shield of Michigan and its Blue Care Network subsidiary excluded GLP-1 drugs for weight management from coverage for fully insured employer group clients effective January 1, 2025. Self-funded employers that contract with BCBS Michigan for administrative services — such as the University of Michigan — were not bound by this decision; their coverage is determined by their own plan documents. The University of Michigan continued its own GLP-1 coverage program under its self-funded plan.

Medicare and federal program changes (3 events)

Two distinct federal pathways created new or expanded GLP-1 access during this period — one through the standard Part D benefit, and one through an entirely separate demonstration program. They operate independently and the distinction matters for authorization, cost-sharing, and which drug presentations are available.

Medicare GLP-1 Bridge — Framework December 12, 2025; Drug Access July 1, 2026 (F05, F13)

CMS published the participant guidance, pharmacy network framework, and drug formulary for the Medicare Obesity Benefit Demonstration — commonly called the GLP-1 Bridge — on December 12, 2025. Drug access under the Bridge began July 1, 2026, with covered beneficiaries paying $50 per month.

Three drugs are available through the Bridge: Zepbound KwikPen, Wegovy, and Foundayo. CMS makes only the Zepbound KwikPen available — the single-dose vial and single-dose pen presentations of Zepbound are not available through the program.

CMS states that the Bridge is a demonstration operating outside the Part D benefit's coverage and payment flow. It is a separate access pathway, not a Part D formulary change. Members using the Bridge do not apply Bridge drug costs toward their Part D deductible or out-of-pocket maximum.

Part D cardiovascular and sleep-apnea indication pathway — January 1, 2026 (F11)

Starting with plan year 2026, Medicare Part D plans may cover semaglutide (Wegovy) when prescribed for cardiovascular risk reduction — an FDA-approved indication granted in March 2024 — and tirzepatide (Zepbound) for obstructive sleep apnea, which received an FDA-approved indication in 2024. This pathway uses standard Part D coverage and cost-sharing, and is entirely separate from the Bridge demonstration. Coverage applies to the indication; a member whose GLP-1 is prescribed only for weight management in Medicare is not covered through this route.

Medicaid changes (1 tracked event + context)

Medicaid GLP-1 coverage is set by each state, varies by indication and eligibility category, and is subject to federal matching rules. Two narrowing events from 2025 fall outside this tracker's primary window but provide important context: MassHealth ended coverage of drugs used solely for obesity or overweight effective July 3, 2025, and Utah's one-year weight-management pilot concluded at the end of June 2025. Both programs retained coverage for GLP-1s prescribed for type 2 diabetes or other approved indications.

Kansas Medicaid — June 1, 2026 (F12)

Kansas Medicaid tightened its prior authorization criteria for GLP-1 drugs used for weight management effective June 1, 2026, adjusting BMI threshold and documentation requirements. Prior authorizations already on file were subject to review against the updated criteria. Kansas is among the states with active GLP-1 Medicaid coverage for qualifying members with obesity; the June 1 revision narrows eligibility without eliminating the benefit.

For a full 50-state analysis of Medicaid GLP-1 prior authorization criteria — including BMI thresholds, comorbidity requirements, step-therapy rules, and managed care variation — see the Medicaid GLP-1 Prior Authorization Criteria by State research page.

Employer plan changes (9 events)

Eleven of the 16 events in this tracker are employer plan actions — decisions made by individual employers about how their self-funded or fully insured benefit plans cover GLP-1 drugs. These actions are not driven by PBM formulary decisions; most large self-funded employers can and do make coverage choices independent of their PBM's standard list.

What employers did and why

The most common employer action in this dataset was an indication restriction — limiting coverage to type 2 diabetes while excluding weight management. Ohio State and the State of Michigan SHP both took this approach. The result is that members prescribed GLP-1s for weight loss may lose coverage while members with the same drug prescribed for diabetes retain it.

The second most common approach was a mandatory program requirement: coverage continues but only if the member concurrently enrolls in a vendor-managed weight-management program. Boston College (Calibrate), Harvard (EncircleRx + 9amHealth), and the University of Michigan all adopted some form of this approach. Programs typically require regular weigh-ins, app engagement, and a documented health plan.

Howard County Public School System chose a phased full exclusion, citing spending growth from $485,000 to more than $3.6 million over two years. NY44 Health Benefits Plan Trust excluded the sole weight-management indication while retaining diabetes coverage, citing cost pressures.

Mayo Clinic was the one employer in this dataset to move in the opposite direction — lifting a prior lifetime maximum for weight-management GLP-1 coverage while simultaneously requiring participation in a Mayo practice-led program. The University of Minnesota maintained coverage and made a product substitution (transitioning members from single-dose pens and vials to Zepbound KwikPen) with no stated coverage gap.

For deeper analysis of employer GLP-1 benefit decisions — including 15 employer profiles across plan types — see the Employers Dropping GLP-1 Coverage: 2026–2027 Data research page.

Presentation-level formulary changes

Three events in this tracker turn on the difference between delivery formats of the same molecule — what the pharmaceutical industry calls "presentations." All three involve Zepbound (tirzepatide):

Prescribers and members need to know which presentation a plan covers before requesting or dispensing. A member whose plan covers Zepbound pens and whose pharmacy only stocks KwikPens may experience a coverage denial even if the underlying drug is on the plan's formulary.

How to read a formulary change

When a plan announces a GLP-1 formulary or coverage change, five questions determine whether and how a specific member is affected:

1. Which drug and which presentation? The change may apply to one brand (Zepbound, Wegovy) or to a class, and within a brand it may apply to only one delivery format (pen, KwikPen, vial).
2. Which indication? A plan may cover the drug for type 2 diabetes but exclude it for weight management, or vice versa. The FDA-approved indication on the prescription must match the covered indication.
3. Which plan? PBM formulary templates are not the same as the plan sponsor's coverage. The member's Summary of Benefits and Coverage or Evidence of Coverage document controls.
4. What happens to existing prior authorizations? The tracker's "PA transition" field describes whether authorizations transferred, terminated, required reapplication, or were subject to criteria review after the effective date.
5. What is the effective date? Changes do not always take effect January 1. Seven of the 16 events in this tracker use a different date.

What this data does not show

Frequently asked questions

How to cite this page

WPG Research Team. "GLP-1 Formulary Changes: The 2025–2026 U.S. Tracker." Weight Loss Provider Guide Research, July 31, 2026. https://weightlossproviderguide.com/research/glp-1-formulary-changes

Dataset version 1.0. Use the version number and dataset cutoff date when citing for reproducibility. Outbound links in the tracker are live as of the verification date above and should be re-checked if cited beyond 90 days.

Primary sources

All sources are primary plan, program, or PBM documents. No secondary or news sources are used. Each row in the tracker maps to the source listed here for that event ID.

Related research

All pages are part of the WPG Research hub — independent, non-commercial reference resources covering GLP-1 access, policy, and coverage. No commercial links.

• Medicaid GLP-1 Prior Authorization Criteria by State — Full 50-state analysis of BMI thresholds, comorbidity requirements, and managed care variation
• State Employee GLP-1 Coverage by State — All 50 state employee health plan GLP-1 benefit policies, with PA criteria and evidence grades
• Employers Dropping GLP-1 Coverage: 2026–2027 Data — 15 employer profiles, 16 plan-level actions, plan-type breakdown, and cost data