Billing for hospital based anesthesia groups, ASC and office based anesthesia teams, CRNA practices and interventional pain physicians.
Anesthesia is the only specialty where the clock sets the fee. Medicare pays base units plus time units multiplied by a locality conversion factor, so a stop time copied from the surgical close, a modifier that disagrees with the CRNA claim, or a nerve block billed without the surgeon request quietly removes money from every case. Most groups never see it, because the claim pays. It just pays less than it should. That is the revenue Luxen goes after first.
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Anesthesia billing services cover coding, claim submission, denial work and AR follow up for anesthesia groups, where payment is base units plus time units multiplied by a locality conversion factor rather than a flat fee per case. Luxen claim audits found anesthesia time was miscalculated on 8% of cases, underbilling a median $61 per case.
Luxen bills for hospital based anesthesia groups working under exclusive contracts, anesthesia teams covering ambulatory surgery centers and office based suites, independent CRNA practices in opt out states, academic and teaching departments reporting resident cases, and interventional pain physicians who run a clinic alongside the operating room schedule.
Billing differs sharply between them. A hospital group lives on concurrency: the anesthesiologist, the CRNA and the schedule have to agree on who directed what, case by case, before either claim goes out. An ASC group bills a professional claim that has to match a facility claim it does not control. A CRNA practice in an opt out state bills QZ and is paid the full allowance, so the whole question is enrollment and documentation rather than modifiers. A teaching department has to separate resident cases from medically directed cases because they are paid differently.
Most groups also bill service lines beyond the anesthetic itself: post operative pain blocks, chronic pain procedures on the office fee schedule, labor epidurals with payer specific time rules, and critical care or line placement performed outside the anesthesia period. Each runs on different rules and each is quoted in the same percentage of collections.
These are the five leaks that show up most often when we audit an anesthesia group before onboarding. Dollar figures use the 2026 Medicare participating anesthesia conversion factor for Florida locality 04, $22.69 per unit, so the arithmetic is checkable against a published fee schedule.
| Scenario | Codes | What goes wrong | $ at stake per claim | Luxen audit finding |
|---|---|---|---|---|
| Anesthesia time stopped at surgical close | 00100 to 01999 | Stop time is copied from the surgeon record, dropping emergence, transport and handoff minutes that still meet the anesthesia time definition in 42 CFR 414.46(a)(3) | 10 lost minutes is 0.67 time units, about $15 per case | Anesthesia time was miscalculated on 8% of cases, underbilling a median $61 per case |
| Modifier pair disagrees across the two claims | AA, QY, QK, QX, QZ | The physician bills QK while the CRNA bills QZ, so the pair claims more than the single case allowance and both lines suspend or recoup | A medically directed pair is paid 50% each, so a mismatch puts the full case allowance at risk | Medical direction modifiers did not match between anesthesiologist and CRNA claims on 5% of cases |
| Post operative block billed without a documented surgeon request | 64415, 64447, 64486 with 59 or XU | NCCI treats the block as part of the anesthetic unless the operating physician transferred pain management responsibility and the anesthetic did not depend on the block | The entire block allowance is denied as bundled | Post operative nerve block claims were denied as bundled on 12% of cases where the surgeon request was not documented |
| Physical status and qualifying circumstance units sent to Medicare | P1 to P6, 99100, 99116, 99135, 99140 | 42 CFR 414.46(b)(3) disallows modifier units for health status, risk, age or unusual circumstances, so the line rejects and can hold an otherwise clean claim | Rework cost on a case that was already going to pay in full | Appeals filed by Luxen were overturned 68% of the time, but this one is avoidable before submission |
| Supervision billed as direction | AD instead of QK | More than four concurrent procedures is medical supervision, paid at three base units, not half of base plus time | A 10 unit case billed QK claims $113.45 where AD allows $68.07, a $45 overstatement and an audit exposure | Our claim audit flags concurrency conflicts against the daily schedule before submission |
Medicare pays anesthesia on a formula almost no other specialty uses. The fee schedule amount is base units plus time units, multiplied by an anesthesia conversion factor specific to the locality. Base units are assigned by CMS to each anesthesia code and cover everything other than time, so they are not reported on the claim. Time units come from the anesthesia time you report.
One time unit is 15 minutes. The contractor computes time units by dividing reported anesthesia time by 15, and it recognizes fractional units. This is the single most misreported rule in the specialty. Reference pages routinely state that each 15 minutes counts as one unit, which is a commercial and workers compensation convention, not how Medicare pays.
Anesthesia time starts when the practitioner begins preparing the patient and ends when the practitioner is no longer furnishing anesthesia services. Blocks of time around an interruption can be added together as long as continuous anesthesia care is furnished in each block, which matters for cases that pause between rooms.
| Step | Calculation | Result |
|---|---|---|
| Reported anesthesia time | 97 minutes | 97 |
| Time units | 97 divided by 15 | 6.47 units |
| Base units for the code | Assigned by CMS, not reported | 6.00 units |
| Total units | 6.47 plus 6.00 | 12.47 units |
| Allowance | 12.47 times $22.69 | About $283 |
| Same case with whole unit rounding | 13.00 times $22.69 | About $295, which Medicare will not pay |
CMS left the anesthesia base units unchanged for 2026, but the conversion factor structure changed. Beginning in 2026 there are three anesthesia conversion factors per locality: a qualifying APM rate, a participating rate and a non participating rate. In Florida locality 04 those are $22.80, $22.69 and $21.56. A group that files against last year's single rate will post variances on every remittance. Our certified medical coding team loads the current locality file before the first claim goes out.
Concurrency is where anesthesia groups lose the most money and take the most compliance risk. The modifier decides what percentage of the allowance each claim receives, and the physician claim and the anesthetist claim have to agree.
| Modifier | Meaning | Medicare payment |
|---|---|---|
| AA | Personally performed by the anesthesiologist | 100% of base plus time |
| QY | Medical direction of one qualified nonphysician anesthetist | 50% |
| QK | Medical direction of two, three or four concurrent procedures | 50% |
| QX | Nonphysician anesthetist with medical direction | 50% |
| QZ | CRNA without medical direction | 100% |
| AD | Medical supervision, more than four concurrent procedures | Three base units, plus one unit if presence at induction is documented |
| QS, G8, G9 | Monitored anesthesia care descriptors | Informational, no payment change |
To bill at the medically directed rate, 42 CFR 415.110 requires the anesthesiologist to do all seven of the following for each patient:
The same regulation requires the physician alone to document that the conditions were met, specifically the pre anesthetic exam, the indicated post anesthesia care, and presence during the most demanding procedures. An attestation signed by anyone else does not satisfy it. Teaching departments are treated separately: since 2010 a teaching anesthesiologist overseeing a single resident case or two concurrent resident cases is paid the full rate, reported AA with GC, not the reduced direction rate. Our coders reconcile the physician claim, the anesthetist claim and the daily schedule before either leaves the billing queue.
Pain blocks are the most commonly denied line on an anesthesia claim, and the denial is almost always correct. The NCCI policy manual treats preoperative evaluation, intraoperative care and routine postoperative evaluation as included in the base unit value of the anesthesia code. A block is separate only when a specific set of conditions is met and documented.
Continuous infusion catheter codes 64416, 64446, 64448 and 64449 include catheter placement. When they are placed for intraoperative pain management they are part of the anesthesia procedure and are not separately reportable on the same date of service. Separately, 01996 for daily hospital management of a continuous epidural or subarachnoid infusion is not reportable on the day the catheter is inserted. Groups that bill 01996 on day zero create a predictable denial on every catheter case.
The practical fix is a documentation rule at the point of care rather than an appeal afterwards. When the surgeon request is captured in the record at the time of the block, the claim is clean on first submission. When it is not, the appeal needs the operative note, the anesthesia record and the surgeon attestation, and our denials and AR recovery team builds that packet. Appeals filed by Luxen were overturned 68% of the time, but a bundled block denial is cheaper to prevent than to win.
The rule is that the contractor divides reported anesthesia time by 15 and recognizes fractional units. Rounding 97 minutes to 7 whole units claims about $12 more per case than Medicare will allow and creates a pattern of overpayments to refund. See 42 CFR 414.46. Our audits found anesthesia time was miscalculated on 8% of cases in both directions.
42 CFR 414.46(b)(3) states plainly that modifier units are not allowed, and names health status, risk, age and unusual circumstances. That covers P1 to P6 and 99100, 99116, 99135 and 99140. Commercial formulas are built differently and include a modifying units term, and some plans allow qualifying circumstance units where a state requires it, including Indiana, Minnesota, North Carolina and Texas. Sending the same claim to both payer types costs rework on every Medicare case.
A medically directed case pays 50% to the physician and 50% to the anesthetist. If one side reports QZ and the other reports QK, the pair claims more than the case is worth and both sides are exposed. Our claim audit found medical direction modifiers did not match between anesthesiologist and CRNA claims on 5% of cases.
Monitored anesthesia care is paid on the same base plus time formula as a general anesthetic. QS is informational. G8 is restricted to a short list of procedures, 00100, 00160, 00300, 00400, 00532 and 00920. Adding them does not raise the allowance, and omitting a required descriptor on a MAC case can trigger a medical necessity review instead.
Medicare claims must be filed no later than one calendar year after the date of service under 42 CFR 424.44. Anesthesia claims held for a missing anesthesia record or an unsigned attestation are the ones that age quietly. Across the practices we review, timely filing caused 6% of denials and only 4% of those were recovered.
We run the revenue cycle from eligibility to zero balance inside the practice management system you already use. How full-service billing works.
Certified coders review charges against your documentation and payer rules before the claim goes out, so the denial is prevented rather than appealed. Medical coding.
Aged and denied claims are worked to resolution, then the upstream cause is fixed so the same claims stop coming back. Denials and AR recovery.
Benefits are verified and authorizations secured before the appointment, which is the cheapest place in the cycle to stop a denial. Eligibility and prior authorization.
Statements, balance questions and payment plans are handled by the same team that worked the claim. Patient billing.
Payer enrollment and re-credentialing are tracked through to approval, so a lapsed credential never quietly stops payment. Credentialing.
A HIPAA-trained front-office assistant working inside your EHR on calls, scheduling, intake and referrals, alongside the billing team. Medical virtual assistant.
We work inside the systems you already run, and there is no migration. On the anesthesia information management side we work in Epic Anesthesia, Oracle Health, Plexus TG, Graphium Health, iProcedures, Medaxion and Shareable Ink. On the practice management and clearinghouse side we work in athenahealth, eClinicalWorks, NextGen, AdvancedMD, Tebra and Availity, and in Surgical Information Systems where the group covers an ASC. Where the group bills a chronic pain clinic alongside the OR schedule, we work in whichever EHR the clinic runs rather than asking you to consolidate. Your anesthesia record, your case log and your schedule stay where they are. We take read access under a signed BAA and work your claims in your system.
2 weeks
from a signed BAA to our team working your claims
About 3 weeks
to the first recovered payments on aged AR
20+ years
combined billing and coding experience
Incomplete start and stop times were causing anesthesia units to be held or underbilled. Luxen reviewed the affected cases, recovered $78,600, and reduced time-related corrections from 10.4% to 2.3%.
Managing Partner, hospital-based anesthesia group
Medical direction and concurrency details were not consistently reflected across simultaneous cases. Luxen introduced a daily schedule audit, reducing modifier-related anesthesia denials by 71%.
Revenue Cycle Director, multi-facility anesthesiology practice
Full engagements are written up in our dental practice case study and our ambulance billing case study.
Anesthesia is named in the regulation. Under 45 CFR 149.420, anesthesiology is an ancillary service, and the notice and consent exception does not apply to ancillary services. An out of network anesthesiologist working at an in network facility cannot ask the patient to waive the protection and cannot balance bill. The patient's cost sharing is calculated at in network rates. For most groups that converted a large book of out of network cases into a payer dispute rather than a patient balance.
The federal independent dispute resolution process is now the route for those cases, and it changed materially in May 2026. The administrative fee dropped from $115 to $15 per party per dispute. Batching is capped at 50 qualified items or services per dispute. The open negotiation notice now has to be submitted through the federal IDR portal to both the other party and the departments, and certified IDR entities have five business days to determine eligibility. Payers have to use standardized claim adjustment and remittance advice codes on remittance to uncontracted providers.
The volume tells you how contested this is. Parties initiated 1,372,563 disputes in the second half of 2025, 16% more than the first half, and providers initiated 76% of them. Providers prevailed in about 85% of payment determinations. At $15 a filing, disputes that were not worth pursuing at $115 now are. The constraint is whether anyone in the practice is tracking eligibility windows and batching correctly, which is exactly what we took over. Patient balances that remain are handled through patient billing with the in network cost share already applied.
3% to 6% of collections
Luxen's pricing generally falls between 3% and 6% of collections, depending on claim volume, specialty, payer mix, and how much of the revenue cycle your practice hands over.
Higher-volume practices usually land toward the lower end. Smaller or more complex practices land higher because there is more work per account. There is no setup fee and no exit fee, and the agreement runs month to month with 30 days notice.
A lower fee attached to weak billing is still expensive. The number that matters is what your collections do after you hire someone.
Luxen charges 3% to 6% of collections. Anesthesia lands in the middle of that range because the unit math and the concurrency reconciliation are more work per claim than a flat fee specialty, and toward the lower end at higher volume.
Take a group collecting $1.8M a year across the OR schedule and a small chronic pain clinic. At 5% that is $90,000 a year. The same range runs $54,000 at 3% and $108,000 at 6%. Across 96 practices under $2M that shared payroll data with us, fully loaded in-house billing cost 7.9% of collections, which on $1.8M is $142,200.
| Line | In house | Luxen at 5% |
|---|---|---|
| Anesthesia professional claims | Included in the loaded cost below | 5% of collections |
| Chronic pain clinic claims | Included in the loaded cost below | Same 5%, no separate rate |
| Coding, clearinghouse, PM license, payroll and benefits | 7.9% of collections | Included |
| Annual cost on $1.8M collected | $142,200 | $90,000 |
| Setup and exit fees | Recruiting and cover for the vacant seat | None, month to month on 30 days notice |
That is a $52,200 difference before anything is recovered. Across 38 client practices, first-pass denial rate fell from 14.2% to 6.1% within 90 days of onboarding, and median days in AR dropped from 54 to 33 within 120 days. Credentialing for new anesthesiologists and CRNAs is quoted separately through credentialing.
Most of the decision comes down to whether the vendor can read an anesthesia record, not whether they can submit a claim.
| Partner type | Anesthesia unit math | Concurrency reconciliation | Contract |
|---|---|---|---|
| In house biller | Depends on one person | Manual, usually after submission | Payroll and turnover |
| Generalist billing company | Often rounds to whole units | Rarely done | Annual, setup fee common |
| Specialty anesthesia company | Handled correctly | Usually done | Annual, often with minimums |
| EHR vendor RCM | Tied to their platform | Limited across facilities | Locked to the software contract |
| Luxen | Fractional units against the current locality file | Daily, before either claim goes out | Month to month, 30 days notice, no setup or exit fee |
If you are running a formal comparison, compare medical billing companies by state before you shortlist. State rules matter more in anesthesia than in most specialties: Nevada Medicaid pays labor epidural codes as an occurrence with no time units, Florida managed Medicaid caps 01967 and 01968 at 360 minutes, and Texas is one of the states where a plan allows qualifying circumstance units that Medicare will not pay. Eligibility and benefit checks that catch those differences before the case run through eligibility and prior authorization.
A 30-minute look at your AR ageing, denial reasons and payer mix. You leave knowing what is recoverable, what we would work first and what it would cost.
We sign a business associate agreement before anyone touches your system. Your named team then works inside the practice management system and clearinghouse you already use. Nothing is migrated, and claims are being worked within two weeks of the signed BAA.
Aged and denied claims come first because that is revenue you have already earned. Most practices see the first recovered payments inside three weeks.
Once the backlog is moving, we take over the agreed part of the daily cycle: eligibility, coding review, submission, posting, denials and patient balances.
You know who owns your claims. The team works inside the practice management system and EHR you already run, with no migration.
Claims are coded by certified coders against your documentation and payer rules. Automation handles the repetitive checks so people spend their time on the claims that need judgment.
We sign a business associate agreement before accessing protected health information, and access is limited to the named people on your account.
We look at your AR ageing, volume, payer mix and denial profile first, then tell you what we believe is recoverable and what it would cost.
A billing company is a poor fit if you are not willing to share visibility into your billing, if the vendor uses a rotating pool of people who never learn your practice, or if it cannot explain why your claims are being denied. Be wary of anyone promising large collection increases before they have seen your AR ageing. The right partner makes your revenue cycle more visible, not less.
Anesthesiologists, certified registered nurse anesthetists and anesthesiologist assistants can all bill, but the modifier decides what each is paid. A personally performed physician case is AA at 100% of the allowance. A medically directed case pays 50% to the physician on QK or QY and 50% to the anesthetist on QX. A CRNA working without medical direction bills QZ and is paid the full allowance.
Luxen charges 3% to 6% of collections, with anesthesia typically in the middle of that range and lower at higher case volume. There is no setup fee, no exit fee and no annual term. For comparison, across 96 practices under $2M that shared payroll data with us, fully loaded in-house billing cost 7.9% of collections.
About two weeks from a signed BAA to working claims, with the first recovered payments arriving around three weeks in. We start on the oldest money first, because 42 CFR 424.44 gives you one calendar year from the date of service to file a Medicare claim and held anesthesia claims are usually the oldest in the file.
No. We work inside the system you already run, including Epic Anesthesia, Plexus TG, Graphium Health, iProcedures and Medaxion, and in your existing practice management system. We take read access under a signed BAA and there is no data migration.
It depends entirely on the payer and the state. There is no single national method for neuraxial labor analgesia time on 01967, 01968 and 01969. Nevada Medicaid pays them as an occurrence with one unit and no time units, while one national managed Medicaid plan pays base plus time with a 360 minute cap in Florida. Billing the same way everywhere guarantees denials in some states.
Thirty minutes, no deck and no fee. We look at what is sitting past 90 days and where your denials cluster, and you leave knowing what is recoverable, what we would work first, and what it would cost.
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