Medicare's GLOBE Model Will Cut Coinsurance on Some Part B Drugs From April 2027. The Patient's Address Decides Who Qualifies.

Most of the coverage of CMS's new GLOBE Model is about drug makers, international prices and Medicare savings. That's fair. Manufacturers are the ones who must take part and pay the rebates. But the model also changes two numbers that a physician practice handles every day: what the patient owes for a drug, and what Medicare pays for it.

CMS published the final rule in the Federal Register on October 2, 2026. The rule takes effect on November 30, 2026. The model starts on January 1, 2027, and CMS says reduced coinsurance amounts for GLOBE Model drugs are in effect from April 1, 2027 to March 31, 2032.

What changes for a practice

The GLOBE Model ties the rebate on certain Part B drugs to an international benchmark. For patients in the model, the coinsurance on those drugs is tied to that benchmark too, so it can fall below the usual 20 percent. Medicare makes up the difference. The final rule's worked example uses a $100 allowed amount: the patient's coinsurance falls from $20 to $10, and the Medicare payment to the provider rises from $80 to $90. The allowed amount itself doesn't change in that example. The split between Medicare and the patient does.

CMS says providers will continue to buy and bill GLOBE Model drugs as usual. The rule doesn't create a new claim form or a new way to order drugs.

Which drugs and which patients

Not every drug, and not every patient:

• Drugs: a subset of Part B rebatable drugs, meaning single-source drugs and biologicals, with more than $100 million a year in Original Medicare spending. CMS's model page names oncology, rheumatology, immunology, ophthalmology and endocrinology among the classes. CMS will post the GLOBE Model drug HCPCS code list on the model website.
• Patients: about 25 percent of Original Medicare Part B beneficiaries, chosen by random selection of geographic areas (ZIP Code Tabulation Areas). CMS checks whether the beneficiary's address of record falls inside a selected area.
• Exclusions: patients in Medicare Advantage and certain other plans aren't in the model, and neither are patients whose primary coverage is another group plan.

The detail that matters most for the front desk is the second one. Model status follows where the patient lives, not where the practice is. A single infusion suite can treat patients from inside and outside the selected areas on the same day, for the same drug, with different coinsurance.

This has happened before

Practices that bill Part B drugs have seen a version of this since April 2023. Under the Medicare Prescription Drug Inflation Rebate Program, CMS publishes a quarterly list of Part B rebatable drugs whose coinsurance is reduced. Practices that updated their patient estimates and posting rules each quarter avoided refunds and confused statements. The GLOBE Model adds a second layer: a reduction that applies only to some patients, depending on their address.

A check to run before April 2027

This is general information, not legal or billing advice for your practice. CMS hasn't yet published every operational detail, so treat this as a preparation list:

• List the single-source drugs and biologicals your practice buys and bills, with their Original Medicare volume. Drugs in oncology, rheumatology, immunology, ophthalmology and endocrinology are the place to start.
• Watch the GLOBE Model page for the drug HCPCS code list and the geographic areas. Compare the list with your own drug list as soon as it appears.
• Stop quoting a flat 20 percent for those drugs from April 2027. A patient's estimate will depend on the drug, the quarter and the patient's address.
• Keep each Medicare patient's address current in your practice management system. If the model follows the address of record, an old address can produce a wrong estimate.
• Ask your billing system vendor how it will handle a higher Medicare payment and a lower coinsurance on the same line, so those payments aren't flagged as overpayments or underpayments.
• Bill the patient and any supplemental plan from the coinsurance on the Medicare remittance, not from your estimate. CMS notes that patients with supplemental coverage may not directly see the reduction, so the secondary claim still needs the right amount.
• Brief the front desk and financial counselors. Patients may read news about lower drug costs and ask why theirs didn't change.

None of this needs to be finished today. It needs an owner, a date in the first quarter of 2027, and a test claim once the lists are out.

Two payers, one line

When Medicare changes the split between what it pays and what the patient owes, small posting errors spread into patient statements, secondary claims and refunds. VOSKPO helps practices check those lines before they turn into credit balances. A revenue review can show where drug payments aren't matching what you expected.