Plus Therapeutics has announced that its wholly owned subsidiary, CNSide Diagnostics, has been enrolled in the Medicare program and assigned a Provider Transaction Access Number (PTAN). This marks a major step toward broader reimbursement for its CNS cancer diagnostic platform.
The enrollment formally establishes CNSide Diagnostics as a Medicare-recognized clinical laboratory, allowing it to submit claims for its CNSide Cerebrospinal Fluid (CSF) Assay Platform, including its tumor cell enumeration (TCE) test.
Reimbursement will be determined by the applicable Medicare Administrative Contractor (MAC), based on whether services are deemed reasonable and necessary.
“Medicare enrollment represents a critical step in our commercialization strategy,” said Russ Havranek, EVP Corporate and Commercial Strategy.
“It enables access to approximately half of the U.S. Medicare population through Traditional Medicare, subject to coverage determinations, while establishing a clear pathway to expand into Medicare Advantage populations over time. Combined with our existing ~81 million commercial covered lives, this milestone strengthens our pathway to broader patient access, adoption, and revenue growth.”
The company framed the development as a turning point in its reimbursement and commercialization strategy, unlocking billing capabilities for Traditional Medicare patients and opening the door to future Medicare Advantage coverage discussions with major insurers, including United Healthcare, Humana, Highmark, and Blue Shield of California.
It also positions the company to advance pricing and coverage negotiations under the Clinical Laboratory Fee Schedule (CLFS) for its newly designated CPT code 0640U, which is expected to support billing beginning July 1, 2026.
Strategic and commercial implications highlighted by the company include: Expanded billing access for Medicare Fee-For-Service patients, subject to MAC coverage decisions; Pathway to Medicare Advantage reimbursement across national and regional health plans; Active engagement with MACs to pursue local coverage determinations (LCDs).
With Medicare enrollment complete, CNSide Diagnostics says its immediate priorities include securing formal coverage determinations from MACs, establishing a payment rate for CPT code 0640U through crosswalk or gapfill methodologies, and expanding payer contracts to reach a target of more than 150 million covered lives by 2026.
The company is also pushing to expand clinical adoption of the CNSide CSF Assay Platform, which detects tumor cells and circulating tumor DNA in cerebrospinal fluid. It is designed to improve diagnosis and monitoring of leptomeningeal metastases, a severe complication of central nervous system cancers.
