Radiation oncology billing KPIs: the six numbers every center should watch, with formulas and the ones specific to radiation therapy
Most lists of radiation oncology billing KPIs are the same six revenue cycle numbers every practice watches, with a benchmark attached and no formula. A radiation center also needs a short set of measures that apply because treatment is delivered in fractions, managed in units of five, authorized by the course and recorded in a system the billing office does not own. This post gives both: the six general numbers with their formulas and sources, and the radiation-specific ones with the arithmetic written out.
If you already track the first six, the second table is the one to take to your next monthly meeting.
The six numbers
Each of these has its own article in our Medical Billing Terms series with the formula, the common measurement errors and a worked example; the table is the summary.
| KPI | Formula | Source data | Published reference points |
|---|---|---|---|
| Days in A/R | Total A/R divided by average daily gross charges (charges for the period, less credits, divided by days in the period) | A/R summary; charges by date range | AAFP: below 50 at minimum, 30 to 40 preferable. MGMA publishes specialty medians in DataDive; its 2026 poll found 43 percent of groups flat, 32 percent higher |
| Clean claim rate | Claims submitted, less 277CA rejections, less first-835 denials for claim errors, divided by claims submitted | 277CA and 835 files | No MGMA or HFMA benchmark; 95 percent is the industry convention |
| Claim denial rate | Claims with a denied line on the first 835 divided by claims remitted (also by line and by dollars) | 835 files | MGMA: 7 to 8 percent first-submission denials over the past four years, below 5 achievable. AAFP: 5 to 10 percent average by dollars, below 5 desirable |
| Net collection rate | Payments net of refunds divided by charges minus contractual adjustments, by date of service, measured at 90 to 120 days | Payment analysis by date of service | AAFP: 95 percent minimum, 95 to 99 average, 12-month window |
| First pass resolution rate | Claims paid correctly on the first response with no rework, divided by claims submitted | Claim history, 277CA, 835, appeal log | No published benchmark; always below the clean claim rate |
| A/R over 120 days | Balance over 120 days divided by total A/R, aged from date of service | Aging report | HFMA MAP Key AR-3 defines the buckets (0 to 30, 31 to 60, 61 to 90, 91 to 120, over 120); MGMA’s Better Performers sit below the median for this share |
Two cautions carry over from the articles. A benchmark is only usable when the formula matches yours, and a radiation oncology practice should compare itself with its own history and with other oncology practices before it compares itself with primary care, because drug charges, authorizations and course-based billing all push days in A/R up for reasons that have nothing to do with the billing office.
The ones specific to radiation therapy
These measures find problems that the six general numbers do not show. Each is a ratio you can build from the treatment system and the billing system, and each should be reviewed by course and by month.
1. Fractions billed versus fractions delivered
Formula: treatment delivery units billed for the month (77402, 77407 and 77412, plus 77371 to 77373 for SRS and SBRT and 77437 and 77438 for superficial therapy) divided by fractions recorded as delivered in the Record and Verify system for the same dates.
The target is 100 percent, and both directions are a problem. Below 100 is unbilled treatment, usually a fraction that was delivered after a plan change and never reached billing, or a course whose charges are being held for an authorization. Above 100 is a duplicate, a fraction billed on a date the machine log does not show, or two units on one date without the BID documentation. Treat the Record and Verify export as correct and check the billing system against it.
2. 77427 units versus fractions
Formula: expected units equal fractions divided by five, rounded down, plus one more unit if three or four fractions remain. Compare with units billed, by course.
A 20-fraction course expects 4 units; a 23-fraction course expects 5; a 22-fraction course expects 4, because one or two leftover fractions do not add a unit. Units above the expected count will be denied with CARC 151 (frequency not supported); units below it are unbilled management. This check only works once the course is closed, because the final unit depends on the total, so run it on courses whose last fraction was in the month. See CPT 77427 for the full rule and Medicare’s own examples.
3. 77387-26 paid rate per fraction
Formula: 77387-26 units paid divided by delivery fractions on which image guidance was performed, by payer. Report billed coverage (77387-26 units billed divided by eligible fractions) and paid share (units paid divided by units billed) separately.
Since January 1, 2026 image guidance is reported only as 77387 with modifier 26, one unit per date of service when guidance was performed, and never with SRS or SBRT, whose delivery codes include guidance. A billed coverage well below 100 percent on an IGRT course means the physician line is not reaching the claim, which the ACCC has flagged as a routing issue from the treatment system to billing. A paid share below billed coverage is a payer problem: a bundling edit, a missing 26 (CARC 4), or a contractor loading error such as the one Palmetto GBA corrected in March 2026. See 77387 modifier 26.
4. Authorization coverage
Formula: courses with an active authorization on file, covering the 2026 codes to be billed, before the first fraction, divided by courses started in the month.
The denominator is courses started, not courses billed, so a course treated without authorization counts against the number even if the authorization arrived later. Since January 1, 2026 Medicare Advantage, Medicaid and CHIP plans owe a standard decision within 7 calendar days and a specific reason for any denial, and every payer’s radiation list was rewritten around 77402, 77407, 77412 and 77387-26, so this number also shows whether the request named the right codes. If it is below 100 percent, review each course that started without authorization. See radiation therapy prior authorization in 2026.
5. Level 3 share of delivery fractions
Formula: 77412 fractions divided by all external beam delivery fractions (77402 plus 77407 plus 77412), by month and by physician.
When CMS set the 2026 rates it assumed 35 percent of delivery would be Level 3 (77412) and 55 percent Level 2 (77407). In the CY 2027 proposed rule it reported that in the first three months of 2026, 77412 was approximately 18 percent of the volume, and proposed to revalue the family on the observed mix. Your own share should be explainable patient by patient: multiple isocenters, active motion management such as gating or breath hold actually used that day, total skin electrons, or mixed electron and photon fields. A share far above 18 percent with a mostly prostate and breast population makes a payer audit more likely; a share near zero in a center that treats left breast with breath hold probably means Level 3 work is being billed as Level 2. See 77407 vs 77412 and the 2027 proposed rules.
6. Days from last fraction to final claim
Formula: for each course closed in the month, the date the final claim was submitted (the last delivery lines and the last 77427 unit) minus the date of the last fraction. Report the median and the worst five.
This is the radiation version of HFMA’s charge lag key (PB-4, days from date of service to posting). Most of the lag comes from course billing: delivery lines wait for the week to close, the last 77427 unit waits for the fraction count, and a hold for a pending authorization can turn into a timely filing problem if no one checks it. A rising median here raises days in A/R a month later.
The monthly review
| Metric | Formula | Pull from | Ask when it moves |
|---|---|---|---|
| Days in A/R | Total A/R divided by average daily charges | A/R summary, charges by date range | Did write-offs rise? Which payer moved? Insurance or patient? |
| Clean claim rate | (Submitted minus 277CA rejections minus error denials) divided by submitted | 277CA, 835 | Which CARC or rejection code grew? Is it one payer? |
| Denial rate (claim, line, dollars) | Denied divided by remitted, three ways | 835 | Which CARC? Which code? Is the dollar figure one drug claim? |
| Net collection rate | Payments divided by (charges minus contractual), by date of service at 90 to 120 days | Payment analysis | Were non-contractual losses posted as contractual? Which payer? |
| First pass resolution rate | Resolved on first response divided by submitted | Claim history, appeal log | What is the gap to clean claim rate, and which payer accounts for it? |
| A/R over 120 days | Over-120 balance divided by total A/R | Aging | Which payer and which CARC make up the balance? |
| Fractions billed vs delivered | Delivery units billed divided by R&V fractions | R&V export, charges | Which courses differ, and in which direction? |
| 77427 units vs fractions | Expected units (fractions divided by 5, final-unit rule) vs billed, closed courses | R&V export, charges | Over or under, and were the overs denied with CARC 151? |
| 77387-26 billed coverage and paid share | Units billed divided by eligible fractions; units paid divided by billed | Charges, 835 | Is the line reaching the claim? Which payer is not paying it? |
| Authorization coverage | Courses authorized before first fraction divided by courses started | Authorization tracker, schedule | Which payer, which code, and how late was the decision? |
| Level 3 share | 77412 fractions divided by all delivery fractions | Charges | Is each 77412 course’s criterion documented? By physician? |
| Days from last fraction to final claim | Final claim date minus last fraction date, median | Charges, R&V | Which courses are the worst five, and what were they waiting for? |
A worked month
An illustrative freestanding center, September.
| Metric | Figures | Result |
|---|---|---|
| Fractions billed vs delivered | 1,248 delivery units billed; 1,260 fractions in R&V | 99.0 percent; 12 fractions on two courses held for a pending Medicare Advantage authorization |
| 77427 units vs fractions | 38 courses closed; expected 262 units; billed 255 | 7 units short on 4 courses, all with 3 or 4 leftover fractions where the final unit was never released |
| 77387-26 billed coverage; paid share | 1,190 units billed on 1,215 eligible fractions; 1,131 paid | 97.9 percent billed; 95.0 percent paid; the unpaid 59 are one commercial payer’s CARC 4 denials for a missing 26 |
| Authorization coverage | 39 of 42 courses started with authorization in place | 92.9 percent; the 3 are the same plan, decisions on days 9, 11 and 12 against a 7-day deadline |
| Level 3 share | 214 of 1,260 fractions on 77412 | 17.0 percent; 11 breath-hold breast courses and 2 total skin electron courses, each with the criterion in the setup note |
| Days from last fraction to final claim | Median 9 days; worst five 31 to 44 days | The worst five are the two held courses plus three where the final 77427 unit waited for a fraction count |
Nothing in the general six would have shown the 7 missing 77427 units, the 59 unpaid guidance lines or the three late authorizations. Together they are a few thousand dollars in a month, and the same problems repeat every month until someone reviews them.
What to do now
- Add the six radiation-specific rows to the monthly report and review them by course, not just as totals.
- Make the Record and Verify export the denominator for fractions, 77427 units and 77387-26 coverage; you cannot check the billing system against its own data.
- Keep a documented Level 3 reason for every 77412 course and review the share by physician each quarter.
- Put the 7-day Medicare Advantage deadline on the authorization tracker and count a course as uncovered until the decision names the 2026 codes.
- Follow up on the worst five courses on last-fraction-to-final-claim every month; they are usually the same two problems.
- Iridium Suite’s reporting can pull the charge, remittance and A/R figures these formulas need by payer and date range, with delivered fractions arriving from the Record and Verify import rather than from a spreadsheet.
Further reading
- HFMA MAP Keys, 2023 edition (PDF): revenue cycle KPI definitions
- MGMA Stat, July 2026: Days in A/R holds steady for most practices, but payer pressure persists
- AAFP: Managing practice finances
- CY 2027 Physician Fee Schedule proposed rule, Federal Register full text (radiation oncology treatment delivery section)
- X12: Claim Adjustment Reason Codes