Why Is Lantheus Stock Trading Lower On Wednesday?

Lantheus Holdings LNTH shares fell Wednesday after U.S. health agencies proposed changes to Medicare payment rules for hospital outpatient services and surgical centers starting in 2026.

The proposal outlines changes in how payment rates are calculated for services under the Hospital Outpatient Prospective Payment System (OPPS) and the ASC payment system.

The CMS has proposed maintaining the $140 packaging threshold for drugs, biologicals, and therapeutic radiopharmaceuticals for calendar year (CY) 2026 under the OPPS and ASC payment system.

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This threshold reflects inflationary adjustments based on the four-quarter moving average of the Producer Price Index (PPI) for prescription pharmaceuticals.

The $140 figure traces back to the $50 threshold established initially under section 1833(t)(16)(B) of the Social Security Act for CYs 2005 and 2006.

CMS first updated this in CY 2007 by trending the $50 forward to CY 2007 using PPI data, rounding it to the nearest $5, and arriving at $55. The same methodology has since been used to update the packaging threshold, including for the CY 2025 rule.

For CY 2026, CMS again applied the same approach, using forecasted PPI data from IHS Global Inc. (IGI), yielding a proposed figure of $141.67, which was rounded to $140.

Additionally, CMS proposes setting the diagnostic radiopharmaceutical packaging threshold at $655 for CY 2026.

This reflects an inflation-adjusted increase from the finalized $630 threshold for CY 2025, using the most recent four-quarter moving average PPI data from the third quarter of 2025 to the third quarter of 2026.

The resulting figure of $654.23 was rounded to the nearest $5.

CMS finalized in the CY 2025 OPPS/ASC final rule that diagnostic radiopharmaceuticals would be paid separately if their per-day cost exceeds the packaging threshold of $630 for that year.

CMS noted that if more recent data becomes available before the CY 2026 final rule is published, the agency may revise the $140 drug packaging threshold and the $655 diagnostic radiopharmaceutical threshold accordingly.

William Blair “believes that Lantheus shareholders will be disappointed by CMS's proposal, especially given that Lantheus management has conveyed the potential for CMS to transition to ASP pricing, which would positively impact the Pylarify franchise.”

Analyst Andy Hsieh on Tuesday said with the CMS finalizing rules on how diagnostic radiopharmaceuticals are reimbursed, concerns around Pylarify losing its pass-through status—and revenue stability—have eased.

The changes mean Pylarify's Medicare-related business should remain largely unaffected, and its leading market position is expected to stay intact.

That said, due to ongoing challenges in securing long-term contracts with partners, Pylarify's growth may stay modest in the short term. Stronger growth likely won't pick up until the second half of the year.

Meanwhile, the company's profitability from its Alzheimer's portfolio depends heavily on how well its commercial products perform.

Price Action: LNTH stock is down 7.77% at $74.95 at the last check on Wednesday.

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