Will any top-3 PBM (CVS Caremark, Express Scripts, OptumRx) exclude tirzepatide from preferred formulary status for 2027?

The resolution criteria requires a formal exclusion, step therapy requirement, or non-preferred tier placement by a top-3 PBM for the 2027 formulary year. While the CVS Q3 2025 disruption (E3) demonstrated that PBMs are willing to restrict tirzepatide access, that event was an access restriction that was resolved — not a full formulary exclusion. The clinical superiority evidence (47% greater weight loss vs Wegovy) provides meaningful formulary leverage. PBMs face significant member backlash risk given tirzepatide's 71% new Rx share. However, the $50/month Medicare deal creates a price reference point PBMs may exploit, and semaglutide provides a legitimate therapeutic alternative. Lilly's willingness to accept -7% pricing suggests they will make further concessions to maintain preferred status rather than risk exclusion. The most likely outcome is continued preferred status with larger rebate concessions, not outright exclusion.

The committee's unresolved debate is directly material: whether PBMs prioritize cost savings over clinical outcomes when therapeutic alternatives exist. The CVS Q3 2025 disruption (E3) proved PBMs are willing to restrict even clinically superior products — this was not theoretical, it happened. The question is whether any PBM escalates from temporary access restriction to formal 2027 formulary exclusion. The $50/month Medicare deal (E2) fundamentally changes PBM negotiating dynamics by establishing a government reference price. If PBMs can point to $50/month and demand comparable commercial discounts, and Lilly refuses, exclusion becomes a credible threat. However, full exclusion of a product with 71% new Rx share and 47% clinical superiority would be unprecedented and would likely trigger significant plan sponsor and member pushback. The more probable scenario is aggressive step therapy or prior authorization requirements rather than outright exclusion — but the resolution criteria does include 'significant step therapy requirements,' which broadens the YES case.

Examining the base rate: PBM formulary exclusion of the leading drug in a major therapeutic category is historically rare. The GLP-1 class is experiencing explosive demand growth, and PBMs that exclude the clinically superior product risk losing plan sponsors to competitors who offer it. The 56% revenue concentration the committee flagged (E3) actually works both ways — it means tirzepatide is so dominant that excluding it creates enormous disruption for patients and providers. Lilly's -7% pricing trend and +50% volume growth (E3, post-earnings) suggest an active strategy of trading price for volume/access — precisely the negotiating posture that prevents exclusion. The CVS Q3 2025 disruption was resolved, indicating that even when a PBM attempts restriction, market forces push toward restoration. The $50/month Medicare deal is relevant but applies to a different payer segment; commercial PBMs negotiate separately. The most likely path is continued preferred status with escalating rebate demands, not formal exclusion.

The CVS Q3 2025 disruption proved PBMs will restrict tirzepatide when it suits their negotiating position. But resolving YES requires formal 2027 formulary exclusion or significant step therapy — a much higher bar than temporary access restrictions. With 71% new Rx share and 47% clinical superiority, any PBM that formally excludes tirzepatide loses competitive positioning with plan sponsors. Lilly's pricing concessions (-7% YoY) show they will pay to maintain access. The broader resolution criteria including step therapy pushes probability up somewhat, but even step therapy for the dominant obesity drug would be commercially risky for PBMs.

I'm weighting the $50/month Medicare deal more heavily than other runs might. This government price creates an anchor that PBMs can exploit: 'If the government gets $50/month, why should we pay more?' This is a new dynamic that didn't exist before April 2026. Combined with semaglutide as a legitimate alternative and the CVS precedent showing willingness to restrict, there's a non-trivial path to at least one PBM imposing significant step therapy (which counts as YES). Express Scripts or OptumRx could use tirzepatide restriction as a negotiating lever to extract concessions from Novo Nordisk on semaglutide pricing. However, the resolution window is 2027 formulary decisions, and these are typically announced Q3-Q4 2026 — giving limited time for the Medicare deal dynamics to fully play out.

The question asks about ANY of the top-3 PBMs, which widens the aperture. But even with three chances, the structural dynamics favor NO. Tirzepatide's clinical superiority is well-documented and supported by real-world evidence. PBMs operate in a competitive market — if one excludes tirzepatide and the others don't, plan sponsors migrate to competing PBMs. The CVS Q3 2025 episode actually reinforces this: CVS tried to restrict access and had to reverse course, demonstrating that market dynamics punish exclusion. Lilly's volume-for-price strategy ensures PBMs can extract value without needing to go nuclear with exclusion.

Clinical superiority (47% > Wegovy) and 71% new Rx dominance make formal exclusion very risky for PBMs. CVS tried restriction and reversed. Lilly is conceding on price (-7%) to maintain access. The $50/month Medicare deal adds negotiating pressure but doesn't change the fundamental calculus that excluding the dominant product hurts PBM competitiveness with plan sponsors.

The resolution criteria is broader than just exclusion — it includes 'significant step therapy requirements.' Step therapy is a more plausible PBM action than outright exclusion, especially as PBMs seek to manage GLP-1 costs. At least one PBM imposing step therapy requiring patients try semaglutide first is a realistic scenario given cost pressures and the Medicare $50/month reference price. Lower confidence because 2027 formulary decisions haven't been announced yet.

Base rate for excluding the dominant drug in a booming category is low. CVS disruption resolved, validating that market forces favor access. Lilly's pricing concessions and volume growth show they prioritize access over margins. Three PBMs checked but competitive dynamics mean each faces same disincentive to exclude unilaterally.