The numbers have been public since December 2025. CMS finalized its CY2026 payment rates, and the arithmetic for ambulatory surgery centers has not changed in the way it needed to. The ASC conversion factor sits at $56.322. The Hospital Outpatient Department (HOPD) conversion factor is $91.415.
Same procedure. Same patient. A $35 difference, every single time.
That is not a policy complaint. That is the operating condition your revenue cycle management software has to work inside. And if it is not built for it, you are bleeding margin on every claim that goes wrong.
Key Takeaways
- ASCs are paid about $35 less per unit than hospitals. That gap puts pressure on your billing team. It makes billing the front line of your facility’s financial survival.
- In 2026, CMS added 573 new procedures to the ASC list. Many are complex spine and heart cases. More complex care means more complex billing.
- At $56 per unit, even small billing errors or delays can cost you more. Payment rates may improve in the future, but not soon.
- Right now, the one thing you can control is how well your billing works.
The Structural Gap Is Not Going Away
The Ambulatory Surgery Center Association (ASCA) has argued for years that the ASC payment system is structurally underfunded relative to inflation-adjusted costs. That position has merit. The gap between $56.322 and $91.415 has persisted even as CMS has recognized ASCs as safe, cost-effective sites for increasingly complex procedures.
The Outpatient Surgery Access Act of 2026, introduced in March, would permanently align ASC rate updates with the hospital market basket methodology rather than the consumer price index. That would slow the rate divergence over time. But it does not close the existing gap. And it is not law yet.
For ASC billing managers today, expected rates and actual collections are two different conversations. Your revenue cycle management software has to perform based on the latter. Those are two different problems. Only one of them is in your control right now.
More Procedures, More Billing Complexity
For 2026, CMS expanded the ASC procedure list by adding 573 new codes. That is a significant expansion — one of the largest in recent memory. Spine and cardiovascular procedures were a central part of that expansion, following years of coordination between ASCA, the American College of Cardiology, and the Heart Rhythm Society.
From a clinical standpoint, this is progress. From a billing standpoint, it introduces complexity. Higher-acuity procedures come with:
- More pre-authorization requirements
- Greater likelihood of payer scrutiny
- More detailed documentation expectations
- Higher denial rates if coding is imprecise
CMS is also phasing out the Medicare inpatient-only list over the next three years. Procedures that once required inpatient hospital settings will gradually be eligible in ASCs. Each newly migrated procedure type brings its own coding norms, payer policies, and prior auth rules.
The volume of procedures billable in an ASC is growing. So is the billing surface area where errors can occur.
The Math Behind a Single Denied Claim
Here is a straightforward way to think about what the conversion factor gap means for billing errors.
At $91 per unit, a denied claim on a 15-unit procedure represents roughly $1,365 in delayed or lost revenue. At $56 per unit, the same denial represents $840. The dollar loss is smaller, but the margin impact is not proportional, because your costs do not scale down with the reimbursement rate. Staff costs, facility overhead, supply costs — those do not adjust because CMS set your conversion factor lower.
That means every dollar of avoidable billing loss hits a thinner margin at an ASC than at a hospital outpatient department. A denial rate that a high-volume HOPD absorbs comfortably can meaningfully strain ASC operations.
And denials are not the only leak. Slow payment posting, charge capture gaps, eligibility verification failures upstream; each of these creates a drag that compounds against a suppressed reimbursement baseline.
What the WISeR Pilot Adds to the Picture
Starting January 1, 2026, CMS launched the WISeR model in six states: Arizona, Washington, New Jersey, Texas, Ohio, and Oklahoma.
This model uses AI and clinical review to check prior authorization requests for some services. These include nerve stimulator implants, epidural injections, spinal procedures, and image-guided lumbar treatments.
For ASCs in these states, this adds a new step. Prior authorizations that were already time-sensitive now face extra review.
CMS plans to test a “gold card” rule by mid-2026. This would reduce reviews for providers with high approval rates. But that is not in place yet.
Right now, WISeR adds friction to certain procedures. This comes at a time when ASC volumes for these services are growing.
If your billing and authorization workflows are not tightly aligned, this can lead to more denials.
What Revenue Cycle Management Software Needs to Do at $56 Per Unit
Given the payment environment: suppressed base rates, expanded procedure complexity, new prior auth requirements, your revenue cycle management infrastructure needs to perform differently than it would in a higher-margin setting.
Specifically, four things matter more at $56 than they would at $91.
Clean Claims On First Submission
A rework loop costs the same in staff time whether your conversion factor is $56 or $91. But at $56, the cost of rework as a percentage of the recovered amount is higher.
Your claims need to be accurate before they leave your system.
Denial Prevention, Not Just Denial Management
Reactive denial management, working claims after they come back, is expensive and slow. At ASC reimbursement levels, the goal should be upstream prevention: eligibility checks, authorization confirmation, coding accuracy.
Denial management is what you do when prevention fails. Prevention should be the primary investment.
Fast Payment Posting
Days in AR are not a neutral administrative metric. Every day a clean claim sits unpaid is cash that is not in your account.
At a $35 per-unit reimbursement disadvantage versus HOPDs, ASCs cannot afford slow posting cycles.
Charge Capture Accuracy
Especially as higher-complexity procedures enter the ASC setting, charge capture gaps become more consequential. Missing a modifier or under-coding a complex case does not just cost the difference on that claim. It skews your payer-level analytics and can create patterns that prompt audits.
These are not aspirational goals. They are operational minimums for a setting where the payment baseline is already constrained.
Learn how billing RCM ops can be structured for ASC environments
The Patient Payment Side of the Equation
Insurance reimbursement is only part of ASC revenue. Patient balances — like copays, deductibles, and coinsurance — make up the rest. At $56 per unit, ASCs have less room to absorb slow or missed payments.
The pattern is familiar. A case is done. An EOB is processed. A bill is mailed. The patient does not respond. Collections start late. Some balances are written off. Each write-off hits an already thin margin.
The fix is to move payment earlier and make it easier for patients to pay.
CERTIFY Pay’s healthcare payment solutions helps you do this. It shows cost estimates before visits, collects payments online, sends reminders, and connects everything to billing and insurance.
In an ASC, this is not optional. It is how you turn patient balances into real revenue.
Explore patient payment workflow options for ASCs.
Drug Pricing Is Worth Watching
CMS set new prices for 10 high-cost drugs starting January 1, 2026, under the Inflation Reduction Act. A new bill could expand this to 50 drugs and may include private insurers.
For most ASCs, this will not affect billing right away. But it matters for centers that handle high-cost drugs, like infusions or complex procedures.
These changes could affect how drugs are priced and paid for in outpatient care. If private insurers follow, ASC margins on these cases could change.
This is something to watch over the next 12 to 24 months. It is not an urgent billing issue today. But ASCs adding cardiac or oncology services should factor this into their plans.
What This Means for Operations
CMS has clearly supported the ASC model. It added 573 new procedure codes. It is phasing out the inpatient-only list. And it continues to move more complex care into ASCs.
But support for the model does not fix the payment gap. The rate difference still exists. Margins are still tight.
As ASCs take on more complex cases, billing becomes more important. Errors, delays, or missed charges hurt more at $56 per unit.
The ASCs that do best will not wait for higher rates. They will build strong billing systems that work well at today’s rates.
Next Step
Schedule a billing efficiency check for your ASC. Find where you’re losing revenue at the rates you actually collect.
Fix gaps in claims, authorizations, and follow-ups to improve cash flow.
