CPT code 84133: Urine potassium, urine specimen2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures potassium in urine to help assess renal potassium handling during evaluation of potassium imbalance, including hypokalemia and suspected renal potassium loss.
Medicare pays $4.73 for 84133 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
$4.73
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 84133 covers
This assay measures potassium in a urine specimen. Clinicians may order it when evaluating hypokalemia, suspected renal potassium loss, or another disorder of potassium balance. The result helps assess how the kidneys are handling potassium alongside the patient’s clinical findings and other laboratory results. Clinical laboratories, including hospital and independent laboratories, perform and report the assay; office-based laboratories may also report it when they perform the test.
Report 84133 for the urine potassium assay performed. Medicare pays this test through the Clinical Laboratory Fee Schedule (CLFS); payment is one national amount per code, without locality or office-versus-facility adjustment. The 2026 national CLFS amount is $4.73, unchanged since 2020. The test is excluded from the physician fee schedule and is paid only through 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 84133
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 84133. 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 84133 with status X (excluded by statute), so the test itself is paid only from the CLFS.
84133 on the lab fee schedule since 2020
84133 · CLFS 2026 Q4 (current)
$4.73
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.
84133 compared with similar tests
- 84132PotassiumSerum, plasma, or whole blood$4.76
- 84132 measures potassium in serum; 84133 measures potassium in urine. Choose according to the specimen tested.
- 84300Urine sodiumUrine specimen$5.06
- 84300 measures urine sodium, not potassium. The assays may be ordered together, but each reports a different urine electrolyte.
- 82436Chloride assayUrine specimen$5.75
- 82436 measures urine chloride. Use 84133 when the analyte measured is urine potassium.
84133 billing questions
When should 84133 be reported instead of 84132?
Use 84133 for potassium measured in urine. Code 84132 identifies potassium measured in serum, so select the code that matches the specimen tested.
What specimen supports 84133?
Report 84133 for an assay of potassium in a urine specimen.
Can urine potassium be reported with urine sodium or chloride?
Yes, when those assays are also performed and documented. Urine sodium and chloride measure different analytes from potassium.
Is a physician interpretation included in 84133?
84133 reports the laboratory assay. Medicare pays it through the CLFS, not the physician fee schedule.
How does Medicare pay for 84133?
Medicare pays one national CLFS amount per code. The amount is the same across localities and does not differ between office and facility settings.
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
Fee sheets
Put 84133 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Build my fee sheet