CPT code 84132: Potassium, serum, plasma, or whole blood2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures potassium in serum, plasma, or whole blood to assess electrolyte status and support evaluation or monitoring of renal, medication-related, and cardiac concerns.
Medicare pays $4.76 for 84132 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
$4.76
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
- QW · CLIA-waived test
- $4.76
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 84132 covers
This blood test quantifies potassium in serum, plasma, or whole blood. Clinicians order it to assess electrolyte balance, investigate suspected high or low potassium, or monitor kidney disease and therapies that can alter potassium. Abnormal potassium can affect muscle function and cardiac rhythm. Hospital and independent laboratories perform the assay; sites holding a CLIA certificate of waiver may perform the waived version.
Report 84132 for an individual blood potassium assay. If the test is performed as part of a basic or comprehensive metabolic panel, report the applicable panel rather than separately reporting its potassium component. Use modifier QW for the CLIA-waived version when applicable. Medicare pays 84132 under the CLFS at one national amount across states and localities, without geographic or office/facility adjustment; the test is paid only under the CLFS. The 2026 national amount is $4.76, unchanged since 2020.
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 84132
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 84132. 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 84132 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 84132 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $4.76.
84132 on the lab fee schedule since 2020
84132 · CLFS 2026 Q4 (current)
$4.76
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.
84132 compared with similar tests
- 84133Urine potassiumUrine specimen$4.73
- 84132 measures potassium in serum, plasma, or whole blood; 84133 is for potassium measured in urine.
- 80048Basic metabolic panelTotal calcium$8.46
- Use 80048 when the basic metabolic panel is performed; potassium is one of its included tests. Use 84132 for the individual blood potassium assay.
- 80053Metabolic panelFourteen blood chemistry tests$10.56
- Use 80053 when the comprehensive metabolic panel is performed; potassium is included. Use 84132 for the individual blood potassium assay.
84132 billing questions
Which blood specimens are covered by this assay code?
The assay measures potassium in serum, plasma, or whole blood. The specimen type does not change the code.
Can 84132 be reported with a metabolic panel?
When potassium is measured as part of a basic or comprehensive metabolic panel, report the applicable panel rather than separately reporting its potassium component.
When should modifier QW be used?
Use QW for the CLIA-waived version when performed by a site holding a CLIA certificate of waiver.
How does Medicare pay for 84132?
Medicare pays the test under the CLFS using one national amount across states and localities, with no geographic or office/facility adjustment.
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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