Inspire Medical Systems, Inc. (NYSE: INSP) stock tumbled sharply on Thursday, December 18, 2025, after a key Medicare coding tailwind that had fueled recent optimism suddenly looked far less certain.
By early afternoon in the U.S. session, INSP was down in the mid-to-high teens, reflecting investor anxiety that a reimbursement “upgrade” tied to a specific billing code may not stick—at least not in the clean, nationwide way many had modeled. MarketBeat
What happened to INSP stock on 18.12.2025?
The immediate catalyst: two Medicare Administrative Contractors (MACs)—CGS and Noridian—reportedly pulled CPT code 64568 for hypoglossal nerve stimulation (HGNS) and redirected billing back toward CPT 64582, according to commentary circulated by Stifel and referenced by multiple market news services.
That matters because a big chunk of the bull case in late 2025 was tied to the 2026 Hospital Outpatient Prospective Payment System (HOPPS)/Ambulatory Surgery Center (ASC) final rule, which had been widely interpreted as lifting facility payments for the procedure under CPT 64568—roughly ~50% for hospitals and ~60% for ASCs year-over-year.
If the market’s new reality is “you’re billing under 64582, not 64568,” then that expected pricing/reimbursement windfall can evaporate fast. Investing.com’s coverage framed the shift as potentially removing a major pricing tailwind for 2026–2027 expectations. Investing.com India+1
Why a billing code can move a medtech stock by ~20%
Medical device investors live in a world where procedure economics can matter as much as product engineering. Inspire sells an implantable therapy for obstructive sleep apnea, and a significant portion of the growth narrative depends on how smoothly hospitals and ASCs get paid—and how much room that creates for device pricing.
Think of reimbursement as the gravity of healthcare: invisible, complicated, and absolutely undefeated.
The specific issue: CPT 64568 vs CPT 64582
Here’s the part many investors missed until it punched the stock in the face:
CMS’ own Medicare Coverage Database includes a Local Coverage Article (A57948) for “Billing and Coding: Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea,” and its revision history states that CPT 64568 was removed as it was “added in error,” effective 12/08/2025. CMS+1
That same CMS article also shows that CPT 64568 had previously been added (earlier revision history references adding it under Group 1 CPT codes per a Change Request), underscoring why there’s been so much confusion and why different parties may have been coding differently.
Meanwhile, the article’s coding guidance explicitly describes implantation under CPT 64582 (with related codes 64583 and 64584 for revision/removal).
Professional societies acknowledge payer variability
The American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) has explicitly noted that:
- Effective Jan. 1, 2026, ASC facility payment for CPT 64568 changes, and CMS assigned 64568 to New Technology APC 1580 in the 2026 HOPPS/ASC final rule.
- ASCs may direct physicians to use 64568 or 64582 depending on payer requirements and contracts.
- LCDs are MAC-specific and can vary by jurisdiction.
Translation: even when the therapy is the same, billing mechanics can be messy—and “messy” is the natural predator of valuation multiples.
Private payers can differ, too
A Providence Health Plan medical policy document (not Medicare, but still relevant for context) argues that since 2022, CPT 64582 is the more appropriate code for the implantation procedure and that it should be used regardless of device model, with modifiers used to reflect reduced service where appropriate.
That doesn’t decide Medicare policy—but it does illustrate why coding alignment can be contested in the real world.
Analyst and Wall Street reactions on 18.12.2025
Today’s downdraft wasn’t just “stock traders being dramatic.” Multiple research notes and news write-ups framed this as a genuine reset of the reimbursement narrative.
Stifel: “details are scant,” but the story could revert to execution
Stifel-linked coverage described the move as a “transition headwind” worsening, with CPT 64568 pulled by two MACs. The implication: if the rest of the MAC ecosystem follows, the big reimbursement uplift thesis loses oxygen. StreetInsider.com+1
Truist: “MAC flip-flop” adds uncertainty
Truist commentary emphasized the uncertainty created by shifting MAC guidance, describing the development as a “flip flop” that raises questions about the coding saga. TipRanks+1
RBC: seeking clarity from CMS; points to the CMS “added in error” language
RBC’s note (as syndicated via The Fly/TipRanks) said Inspire is seeking clarity, and highlighted CMS website language indicating 64568 was removed as added in error—an argument that aligns with what the CMS revision history shows.
Piper Sandler: surprised, but expects policies to be updated again
Piper Sandler coverage described the removal as unexpected and suggested the policies may be updated to include CPT 64568 again, reflecting a “this is fixable” interpretation of the disruption. TipRanks+1
INSP stock price today: volatility in black and white
INSP traded with extreme volatility on Dec. 18, swinging between roughly the high $80s and the low $100s during the day, according to market data feeds.
That kind of range is the market screaming one message: “We don’t know which reimbursement model is real yet.”
Inspire Medical Systems fundamentals: what hasn’t changed
Even as reimbursement headlines dominate, Inspire’s underlying business remains a real operating company with real numbers:
- In Q3 2025, Inspire reported $224.5 million in revenue (up 10% year over year) and 85.8% gross margin.
- The company reaffirmed full-year 2025 revenue guidance of $900–$910 million and raised diluted net income per share guidance to $0.90–$1.00.
So the debate isn’t “does Inspire have a product?” It’s “what does the reimbursement environment allow that product to earn per procedure—and how consistent will that be across geographies and sites of care?”
Forecasts and price targets: what the Street expects now
Despite today’s drop, aggregated Wall Street forecasts still skew positive—though dispersion is wide.
MarketBeat’s consensus (based on 19 analyst ratings over the last 12 months) shows:
- Consensus rating: Moderate Buy
- Average 12-month price target:$138.88
- High / Low targets:$197.00 / $85.00
That huge range is basically an uncertainty map. In plain English:
- If reimbursement and coding align favorably, INSP has room to rebound.
- If the favorable code pathway is blocked—or becomes fragmented—targets compress quickly.
What investors should watch next
This story will likely move on documents, not vibes.
Here are the next likely catalysts for INSP stock:
- CMS clarification and/or updated articles/transmittals
The CMS Medicare Coverage Database already shows a documented correction removing 64568 “as added in error.” Whether that’s the final word—or a temporary cleanup before a new, more formal pathway—matters a lot. CMS+1 - MAC-by-MAC alignment (or fragmentation)
Today’s shock came from two MACs. The market will quickly price in whether this becomes a broad standard, a regional inconsistency, or a short-lived update. - Site-of-care economics: hospitals vs ASCs
AAO-HNS notes that the 2026 payment change for CPT 64568 applies to ASC facility reimbursement and references new technology APC 1580. If the “right” code differs by payer/site, the commercial impact could be uneven. AAO-HNS - Company commentary (next earnings call, investor communication)
Investors will be listening for procedural volume trends, any reported friction at implanting centers, and how Inspire plans to navigate pricing under an uncertain reimbursement framework.
A separate but ongoing headline: securities litigation updates
Alongside reimbursement volatility, law firms continued to publish investor notices relating to a securities fraud class action tied to earlier company disclosures and a prior large stock decline (separate from today’s coding news).
These announcements don’t necessarily change day-to-day fundamentals—but they can add background noise and risk sensitivity, especially during periods when the stock is already swinging hard.
Bottom line for INSP stock on 18.12.2025
Inspire Medical Systems stock didn’t drop because investors suddenly stopped believing in sleep apnea treatment. It dropped because a core “math input” (reimbursement and coding) got thrown into doubt—and for medtech, that can be as consequential as an earnings miss.
The next move likely depends on whether the CPT-code situation resolves into a stable, favorable standard—or stays a patchwork that limits pricing power.
