CPT code 84545: Urea clearance, clearance calculation2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures urea nitrogen clearance using blood and timed urine results to assess kidney function when a clinician orders a clearance study.
Medicare pays $7.20 for 84545 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$7.20
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2020
- Unchanged
- CMS updates
- Quarterly
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 8 sections
What 84545 covers
A urea nitrogen clearance study evaluates kidney function by relating urinary urea nitrogen excretion to its level in blood. It typically uses a timed urine collection, urine volume, and a blood specimen. Physicians evaluating kidney function may order the study, and clinical laboratories perform or report the laboratory testing and clearance result.
Report 84545 for the clearance study rather than for a standalone blood or urine urea nitrogen measurement. Medicare pays the test only through the Clinical Laboratory Fee Schedule (CLFS). The 2026 national CLFS amount is $7.20, unchanged from 2020 through 2026. The amount is the same across states and localities, with no geographic or office-versus-facility adjustment. The physician fee schedule classifies the test as paid only from the CLFS.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 84545
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 84545. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 84545 with status X (excluded by statute), so the test itself is paid only from the CLFS.
84545 on the lab fee schedule since 2020
84545 · CLFS 2026 Q4 (current)
$7.20
Unchanged since Jan 1, 2020
27 quarterly CLFS releases on file, first CLFS 2020 Q1. A code missing from a quarter wasn’t on that release.
84545 compared with similar tests
- 84520Blood urea nitrogenQuantitative assay$3.95
- Choose 84520 for a urea nitrogen assay alone. Choose 84545 when the service determines urea nitrogen clearance.
- 84540Urine urea nitrogenUrine specimen$5.56
- 84540 reports a urine urea nitrogen assay; 84545 reports a clearance study using blood and urine measurements.
- 82575Creatinine clearanceTimed urine and serum$9.46
- 82575 measures creatinine clearance, while 84545 measures urea nitrogen clearance. Select the code for the analyte and clearance study performed.
84545 billing questions
When should 84545 be selected instead of 84520?
Use 84545 when the service determines urea nitrogen clearance. Code 84520 describes a urea nitrogen assay without the clearance determination.
How does 84545 differ from 84540?
84545 reports a urea nitrogen clearance study. Code 84540 reports a urine urea nitrogen assay when a clearance result is not being reported.
What specimens are used for the clearance study?
The study typically uses a timed urine collection and a blood specimen for urea nitrogen measurement, along with urine volume and collection time for the clearance calculation.
How does Medicare pay for 84545?
Medicare pays it through the CLFS at one national amount per code, without geographic or office-versus-facility adjustment. It is paid only through the CLFS.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
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