Roughly one in four people on Original Medicare Part B is about to be sorted into a new drug-pricing experiment by nothing more than the address on file with Medicare. Nobody signs up, nobody is asked, and as of today nobody outside CMS can say who is in. The model is final, it carries a Federal Register date of October 2, 2026, and the patient-facing part begins on April 1, 2027.
A final rule, and a quarter of Part B enrollees on Original Medicare
The Global Benchmark for Efficient Drug Pricing Model, known as GLOBE, is a final rule published in the Federal Register on October 2, 2026, not a proposal. It takes effect November 30, 2026. CMS writes that the model covers “approximately 25 percent of beneficiaries who are enrolled in OM Part B,” with OM meaning Original Medicare. The quarter is therefore a share of Original Medicare Part B enrollees, not a quarter of every Medicare member and not a quarter of the country.
Two groups sit outside that quarter by definition. Anyone in a Medicare Advantage plan, a section 1876 cost plan or a section 1833 health care prepayment plan is excluded, and so is anyone whose primary payer is other group health coverage, such as an employer plan that pays first. CMS also states that selection of the cohort “will be solely determined by CMS and will not be subject to appeal.”
Selection by ZIP Code Tabulation Area, not by plan or by choice
The draw is geographic and random. The rule calls for “a random selection of ZIP Code Tabulation Areas,” known as ZCTAs, which are the Census Bureau’s approximations of postal ZIP codes. In the CMS frequently asked questions, a beneficiary lands in the model when the address of record in the Medicare Beneficiary Database falls inside one of the chosen areas. The selection is by ZCTA, not by state, county or hospital region, so two neighbors can end up on opposite sides of a line.
No ZIP codes have been named yet. The same FAQ promises that “the GLOBE Model ZIP Codes List will be available by January 16, 2027,” about 11 weeks before the reduced coinsurance begins, so that beneficiaries and providers can “anticipate whether they may be eligible.” The FAQ is plain that “beneficiaries cannot and do not have to do anything to be eligible for GLOBE Model reduced coinsurance.”
Drugmakers are the ones the rule compels
The word “mandatory” attaches to manufacturers. Producers of the covered drugs must take part, while the rule says Medicare beneficiaries “will not be model participants but will benefit from reduced coinsurance.” CMS’s own September 30 press release describes the model more loosely as mandatory for selected beneficiaries in designated areas, which is why the two documents can sound as if they disagree. CMS Administrator Dr. Mehmet Oz said in that release that “Medicare Part B patients and American taxpayers have paid significantly more for prescription medications than people in comparable countries.”
The benchmark comes from 19 reference countries: Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, France, Germany, Ireland, Israel, Italy, Japan, the Netherlands, Norway, South Korea, Spain, Sweden, Switzerland and the United Kingdom. That foreign-price machinery works on the manufacturer side. For a patient, the visible result is a different coinsurance percentage.
What changes on the bill for a Part B drug on April 1, 2027
Part B drugs are the ones usually administered in a doctor’s office, infusion suite or hospital outpatient department, and Original Medicare normally leaves the patient with 20 percent coinsurance. Under GLOBE, eligibility “will be determined by CMS at the time a claim for a GLOBE Model drug is processed for Medicare payment,” according to the FAQ, and the remittance advice sent to the provider identifies the beneficiary’s coinsurance liability. In practice, the first sign for a patient in a selected area would be a smaller coinsurance line on a covered drug, with no card, enrollment form or notice required.
Not every infused drug qualifies. The rule limits the model to single source drugs and sole source biologicals in seven classes: antigout agents, antineoplastics, blood products and modifiers, central nervous system agents, immunological agents, metabolic bone disease agents and ophthalmic agents. A billing code must also show more than $100 million in Original Medicare Part B spending over 12 months. Orphan-only drugs, plasma-derived products, cell and gene therapies, drugs with negotiated maximum fair prices and biosimilars are excluded.
Using 2024 illustrative data, the rule estimates that “94 percent of illustrative GLOBE Model drugs would have a beneficiary coinsurance percentage between 2 and 12 percent,” well below the standard 20 percent. The FAQ adds that the actual effect depends on circumstances such as supplemental insurance, and it does not spell out how Medigap policies interact with the lower percentage.
Five dates that are easy to confuse
The rule is effective November 30, 2026. The CMS GLOBE model page lists the model start as January 1, 2027, when manufacturer reporting begins, and the reduced coinsurance period as April 1, 2027 through March 31, 2032. The ZIP list is due by January 16, 2027. Rebate invoicing and reconciliation then run into 2034, which is why the rule counts a seven-year payment period alongside the five-year performance period.
The Federal Register estimates the model will save beneficiaries $177 million in out-of-pocket costs over that seven-year payment period, alongside $440 million in Part B savings and $39 million in Medicaid savings. Questions about the model go to CMS’s Nicholas Minter at [email protected], the contact named in the final rule.
Tracking Part B drug coinsurance before the ZIP list arrives
The GLOBE final rule leaves Original Medicare patients waiting until January 16, 2027 to learn whether their ZIP Code Tabulation Area was drawn, with reduced coinsurance on covered Part B drugs set to start April 1, 2027. Until then, the unfinished job is knowing what each drug costs now and which costs are worth tracking against that April change.
The Medicare Cost & Coverage Protection Kit includes a medication and cost tracker and 51 state Medicare cost-help packs, which line up drug spending and state-run help in one place.
Open the tracker that puts today’s Part B drug costs on paper before April →
This piece was drafted with AI assistance; the figures were checked against the Federal Register final rule and CMS’s GLOBE press release, FAQ and model page.
