Disclosure: Weight Loss Wire is an independent educational publisher. We may have a financial affiliation with some entities featured on this page. This article is educational only and is not medical advice.
The short answer: A PBM formulary is the list of drugs your plan covers and on what terms. When a PBM moves a GLP-1 on or off its preferred list, coverage may shift to a different drug, need new prior authorization, or cost more or less. Checking your plan’s current formulary and asking about transition or exception rules tells you where you stand.
What is a PBM, and what is a formulary?
A pharmacy benefit manager (PBM) is a company that runs the prescription drug part of a health plan. Employers, unions, insurers, and government programs hire PBMs to negotiate drug prices with manufacturers, process pharmacy claims, and build the drug lists their plans use. CVS Caremark, Express Scripts, and Optum Rx are the largest PBMs in the U.S.
A formulary is that drug list. HealthCare.gov defines it as “a list of prescription drugs covered by a prescription drug plan or another insurance plan offering prescription drug benefits,” also called a drug list (HealthCare.gov glossary, checked Sept. 28, 2026). A formulary also sets the terms for each drug, such as which cost-sharing tier it sits in and whether it needs prior authorization or has quantity limits.
One detail matters a lot for GLP-1 coverage. Large PBMs publish template formularies, and the employer or plan that hired the PBM (called the plan sponsor) decides whether to adopt the template as-is, customize it, or leave out a category entirely. CVS Health says this directly in its announcement: “Plan sponsors that adopt CVS Caremark template formularies retain discretion to customize coverage for their members” (CVS Health, May 28, 2026, checked Sept. 28, 2026). A PBM changing its template does not by itself change your plan. Your plan’s own choices do.
What changes on Oct. 1, 2026, at CVS Caremark?
On May 28, 2026, CVS Health announced updates to CVS Caremark’s most common commercial formularies. According to that release, checked on Sept. 28, 2026:
- Zepbound (tirzepatide) returns Oct. 1, 2026. CVS Caremark said it “will add Zepbound back to our commercial formularies as an additional preferred option October 1, 2026,” for plan sponsors that elect to cover weight-management medications (CVS Health release; investor version).
- It is described as an “additional” preferred option. Trade press covering the announcement reported that Wegovy (injection and pill) keeps its preferred status and that members currently on Wegovy can continue without interruption (Managed Healthcare Executive, checked Sept. 28, 2026).
- One related change took effect earlier. CVS Caremark said it would remove its new-to-market block on Foundayo (orforglipron), an oral GLP-1, effective June 1, 2026, where plans approve coverage. For drug details, see the manufacturer’s label rather than this article.
- Background. Zepbound had been dropped from those template formularies in 2025, when CVS Caremark made Wegovy its preferred weight-management GLP-1 (Managed Healthcare Executive).
CVS Caremark also said it would provide “advanced communication and/or support to customers, consultants, providers and members” around the change. If your plan adopted the update, you may receive a letter or portal notice. If you don’t, that doesn’t necessarily mean nothing changed, so it’s still worth checking.
We use this change as an example because it is well documented and has a fixed date. The same questions apply to any PBM formulary update, at any plan.
What do “preferred,” “non-preferred,” and “excluded” mean?
Plans use slightly different words, but most formularies sort drugs into a few groups:
- Preferred. The drug is on the formulary at the plan’s more favorable terms, usually a lower copay or coinsurance tier. Preferred does not mean automatic approval. A preferred GLP-1 can still require prior authorization, step therapy, or quantity limits.
- Non-preferred. The drug is covered, but usually at a higher cost-sharing tier, and sometimes only after you’ve tried a preferred option first (called step therapy).
- Excluded or non-formulary. The plan doesn’t cover the drug on its standard terms. Coverage may still be possible through a formulary exception, which your prescriber requests and the plan decides.
Two more terms show up next to drug names in formulary documents:
- Prior authorization (PA). The plan must approve the drug before it pays. HealthCare.gov notes that preauthorization “isn’t a promise your health insurance or plan will cover the cost” (HealthCare.gov glossary, checked Sept. 28, 2026). Our step-by-step guide to how prior authorization for GLP-1s works publishes Oct. 1.
- Quantity limit (QL). The plan caps how much it covers in a set period.
Many formulary PDFs show these as abbreviations such as “PA,” “ST,” and “QL” beside each drug. The legend is usually on the first few pages.
How do I check my own plan’s formulary?
Because plan sponsors customize templates, the only reliable answer comes from your own plan’s current documents. Here are the usual ways to check, roughly from fastest to most definitive:
- Log in to your pharmacy benefit portal. The PBM name is usually printed on your insurance card (often on the back, near the pharmacy “Rx BIN” and “PCN” numbers). CVS Caremark members can sign in at Caremark.com and look up a drug’s coverage and estimated cost. Other PBMs have similar tools.
- Find your plan’s formulary document. Most plans post a drug list PDF. Check the effective date on the cover, because PBMs often publish updated lists quarterly or at the start of a plan year.
- Call the member services number on your card. Ask specifically about the drug your clinician prescribed, and write down the date, the representative’s name, and any reference number.
- Ask your HR or benefits team. If you get coverage through work, your employer is the plan sponsor, and HR can tell you whether the plan adopted a PBM’s template change and whether it covers weight-management drugs at all.
Questions worth asking, whatever the drug:
- Is the drug covered for my diagnosis on the date I plan to fill it?
- What tier is it on, and what will I pay per fill?
- Does it require prior authorization, step therapy, or quantity limits?
- If I already have an approval for a different drug, does it carry over, or is a new request needed?
- Is there a transition fill or continuity policy if my current drug’s status changes?
- How does the formulary exception process work, and where are the forms?
What happens with exceptions, transition fills, and prior authorization?
When a formulary changes, plans usually have rules for people who were already filling a drug. The details are plan-specific, so ask your plan rather than assuming. In general terms:
- Transition or continuity fills. Some plans cover a limited supply of a drug whose status changed so there’s time to sort out next steps. Whether this applies, and for how long, depends on your plan.
- Prior authorization may not carry over. An approval is usually tied to a specific drug. If you and your clinician decide to use a different medication after a formulary change, expect that the plan may require a new request. Whether an alternative fits you is a decision for your clinician, not your formulary.
- Formulary exceptions. If a drug is excluded or non-preferred, your prescriber can usually ask the plan to cover it anyway, with a statement of medical reasons. Medicare drug plans describe this process on Medicare.gov; commercial plans have their own versions.
- Denials and appeals. If a request is denied, the plan has to tell you why and how to dispute it. HealthCare.gov explains internal appeals and external review in How to appeal an insurance company decision (checked Sept. 28, 2026).
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What this doesn’t tell you
A PBM announcement tells you what a template formulary will allow. It does not tell you whether your employer or insurer adopted it, whether your plan covers weight-management drugs at all, what you personally will pay, or whether any drug is right for you. Plans can also change their benefits at renewal. Treat every formulary fact as dated, and re-check it before you fill a prescription. For more on plan coverage, visit our Insurance & Coverage hub.
FAQ
Does Zepbound’s return to CVS Caremark’s formulary mean my plan covers it on Oct. 1?
Not necessarily. CVS Caremark changed its template commercial formularies, and plan sponsors can adopt or customize them. Your plan also has to cover weight-management drugs in the first place. Check your portal or call the number on your card.
Is a “preferred” drug automatically approved?
No. Preferred usually means more favorable cost-sharing, but the drug can still require prior authorization, step therapy, or quantity limits.
How do I find out which PBM runs my plan?
Look at your insurance card for a pharmacy section or PBM logo, or ask your plan’s member services or your HR benefits team.
If my plan changes its preferred GLP-1, do I have to switch medications?
A formulary change affects what your plan covers and at what cost. It doesn’t decide your treatment. Your clinician decides whether an alternative fits, and your plan can explain any transition or exception options.
How often do formularies change?
PBMs and plans can update drug lists during the year, and many make larger changes at the start of a plan year. The effective date printed on your formulary document tells you which version you’re looking at.
Sources (checked Sept. 28, 2026)
- CVS Health, “CVS Caremark delivers affordability and access to GLP-1 weight management medications with expanded coverage options,” May 28, 2026. https://www.cvshealth.com/news/company-news/cvs-caremark-delivers-affordability-and-access-to-glp-1-weight-management-medications-with-expanded-coverage-options.html
- CVS Health investor release (same announcement). https://investors.cvshealth.com/news/news-details/2026/CVS-Caremark-Delivers-Affordability-and-Access-to-GLP-1-Weight-Management-Medications-with-Expanded-Coverage-Options/default.aspx
- Managed Healthcare Executive, “CVS Caremark to put Zepbound back on formulary and add Foundayo.” https://www.managedhealthcareexecutive.com/view/cvs-caremark-to-put-zepbound-back-on-formulary-and-add-foundayo
- HealthCare.gov glossary, “Formulary.” https://www.healthcare.gov/glossary/formulary/
- HealthCare.gov glossary, “Preauthorization.” https://www.healthcare.gov/glossary/preauthorization/
- HealthCare.gov, “How to appeal an insurance company decision.” https://www.healthcare.gov/appeal-insurance-company-decision/
- Medicare.gov, “Appeals in Medicare drug plans.” https://www.medicare.gov/providers-services/claims-appeals-complaints/appeals/drug-plans
- CVS Caremark member site. https://www.caremark.com/
Weight Loss Wire is an educational publisher, not a clinic or insurer. Nothing here is medical, legal, or insurance advice. Coverage details vary by plan and can change; confirm with your plan.
Disclosure: We may have a financial affiliation with some entities featured on this page.