Will Your 2027 Part B Drug Costs Actually Go Down?

Yesterday the Centers for Medicare and Medicaid Services finalized a new, mandatory pricing model for certain drugs covered under Medicare Part B — the physician-administered medications used for conditions like cancer, rheumatoid arthritis, and macular degeneration, not the pills you pick up at a pharmacy. The Global Benchmark for Efficient Drug Pricing, or GLOBE, Model ties certain Part B drug rebates to prices paid in other developed countries, starting in 2027. The headline sounds like straightforward good news. The fine print tells a more complicated story: the savings CMS now projects are a small fraction of what the agency projected when it first proposed this same model last December.

What GLOBE actually does

The Global Benchmark for Efficient Drug Pricing Model targets a specific, often-overlooked category of Medicare spending: drugs and biologics that are administered by a clinician in a medical setting rather than picked up at a pharmacy counter. Think chemotherapy infusions, injectable treatments for rheumatoid arthritis, eye injections for macular degeneration, and similar Part B-covered biologics. CMS has pointed to real pressure in this category: according to HHS's Office of the Assistant Secretary for Planning and Evaluation, cited in CMS's own announcement, Original Medicare Part B drug spending grew nearly four times as fast as drug spending across all payers combined between 2008 and 2021.

The model works by changing how Medicare calculates the inflation rebate manufacturers owe when they raise prices faster than inflation on certain Part B drugs. Instead of using the current formula alone, GLOBE will test an alternative benchmark drawn from prices paid in other economically comparable countries. Dr. Oz said Medicare Part B patients and taxpayers have long paid more for these drugs than people in comparable countries.

Importantly, GLOBE won't touch every Part B drug, and it won't touch every beneficiary. CMS excluded biosimilars and the brand-name biologics they compete with once a biosimilar is on the market, along with orphan-only drugs, plasma-derived products, and certain cell and gene therapies — carve-outs the agency added specifically in response to public comments on the original proposal. And geographically, the model only applies to beneficiaries in a randomly selected set of ZIP code areas, covering roughly a quarter of people with Original Medicare Part B as their primary coverage. If you're not in one of those areas, this model doesn't apply to your Part B drug costs at all, regardless of what drugs you take.

Source: CMS press release, September 30, 2026

Who's actually affected, and when

Two filters determine whether GLOBE touches your Part B costs at all: where you live, and what drug you take.

Geography comes first. CMS selected a random subset of ZIP Code Tabulation Areas for the model, covering about 25% of Original Medicare beneficiaries nationally. There's no way to know in advance from this article whether your specific ZIP code is included — that detail is expected to be published alongside the model's implementation materials at CMS's GLOBE Model page as 2027 approaches. If you're not in a selected area, none of this changes what you pay for Part B drugs, regardless of what you're prescribed.

Drug category comes second. Even within a selected area, GLOBE only applies to certain separately payable Part B drugs and biologics — broadly, medications in categories like oncology, rheumatology, immunology, ophthalmology, and endocrinology, administered by a clinician rather than filled at a pharmacy, per a same-day industry roundup. Routine prescription drugs you pick up at a pharmacy, covered under Part D, are entirely unaffected by this model.

For beneficiaries who do fall into a selected area with a covered medication, CMS says reduced out-of-pocket costs could begin showing up as early as April 1, 2027 — three months after the model itself starts on January 1, 2027. The model's core operating period runs through March 31, 2032, a five-year span, though manufacturer rebate invoicing and reconciliation continues for two additional years beyond that, through March 31, 2034. Both the five-year and seven-year figures you may see reported elsewhere are accurate; they're describing different parts of the same timeline, not conflicting claims.

Source: CMS press release, September 30, 2026

Why the savings estimate collapsed

The gap between $8.4 billion proposed and $440 million final is large enough to deserve its own explanation, and the answer is mostly about scope.

When CMS proposed GLOBE in December 2025, the rule as written would have applied more broadly. Public comments raised concerns about specific drug categories where the new international-benchmark rebate formula could create problems — orphan drugs developed for small patient populations where there's limited ability to raise prices without undermining the business case for developing them in the first place, biosimilars still establishing themselves against entrenched reference biologics, plasma-derived products with their own distinct manufacturing economics, and cell and gene therapies representing some of medicine's newest and most complex treatments. CMS's final rule carved all of these out.

Each exclusion removes real drug spending from the model's reach, and together they appear to account for a substantial share of the gap between the original $8.4 billion projection and the final $440 million figure. That's a defensible outcome from a policy standpoint — the comment process exists specifically to catch unintended consequences before a mandatory rule takes effect — but it also means the version of this program that actually launches in 2027 is a considerably smaller intervention than the one originally announced.

There's a broader pattern worth naming plainly: proposed federal rules routinely scale back between initial proposal and final publication, as public comment periods surface real-world complications. We've tracked a similar dynamic in 2027 Medicare Advantage payment policy, where an initially modest payment proposal ended up finalized at a higher number after industry pushback — the opposite direction from GLOBE, but the same underlying lesson: a proposed rule's headline numbers are a starting point for negotiation, not a reliable preview of the final outcome.

Source: Becker's Hospital Review, September 30, 2026

What to actually watch for between now and 2027

Nothing about this model requires you to do anything right now, but a few concrete things are worth tracking as 2027 approaches.

Watch for CMS to publish which specific ZIP code areas are included in the model. That information is expected on CMS's GLOBE Model page as implementation details firm up. Once it's public, you'll be able to check whether your own area is affected directly, rather than relying on national averages or projections.

If you take a clinician-administered Part B drug in one of the targeted categories — oncology, rheumatology, immunology, ophthalmology, or endocrinology — ask your provider's billing office whether they're aware of GLOBE Model participation as 2027 approaches. Practices that bill Medicare for these drugs will likely have earlier visibility into implementation details than individual patients will.

Treat any "your drug costs will drop dramatically" messaging around this program with appropriate skepticism. The realistic savings CMS itself now projects, $440 million against an original $8.4 billion estimate, are modest relative to overall Part B drug spending, concentrated in specific places and specific drug categories, and not something every Medicare beneficiary will experience.

If you want to track this alongside everything else changing in 2027, our 2027 Medicare hub is where we're keeping the full picture in one place, including what's happening with Medicare Advantage premiums and plan availability and how Part B premiums compare to your Social Security raise next year.

Source: CMS GLOBE Model page

Table 1 — GLOBE Model: proposed vs. final

Table 2 — GLOBE Model timeline

Sources: CMS press release; Becker's Hospital Review