CPT code 82438: Chloride assay, other fluid source2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures chloride in a nonblood, nonurine fluid, including sweat testing reported during evaluation for cystic fibrosis.
Medicare pays $5.00 for 82438 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
$5.00
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 82438 covers
This assay measures chloride in a fluid source other than blood or urine. Sweat chloride testing is a recognized use in evaluating cystic fibrosis. For this testing, sweat is collected—commonly following pilocarpine iontophoresis—and analyzed for chloride. The specimen type distinguishes this assay from codes for blood and urine chloride. Clinicians may order it as part of a cystic fibrosis evaluation, and the laboratory reports the chloride analysis for the submitted specimen.
Report 82438 for the chloride analysis of an other-fluid specimen; do not use it for blood or urine chloride testing. Sweat collection may be reported with 89230 when that collection service is performed. Medicare pays this test only through the CLFS. The 2026 national CLFS amount is $5.00, unchanged from 2020 through 2026. The same amount applies across states and localities, with no office or facility difference. The test is excluded from the physician fee schedule.
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 82438
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 82438. 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 82438 with status X (excluded by statute), so the test itself is paid only from the CLFS.
82438 on the lab fee schedule since 2020
82438 · CLFS 2026 Q4 (current)
$5.00
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.
82438 compared with similar tests
- 82435Chloride testBlood specimen$4.60
- Choose this code for a blood chloride assay. Use 82438 when the tested fluid is neither blood nor urine.
- 82436Chloride assayUrine specimen$5.75
- Choose this code for a urine chloride assay. Use 82438 for chloride measured in another fluid source, such as sweat.
- 89230Sweat collectionSpecimen collection only$2.47–$4.03
- This code represents sweat collection by iontophoresis, not the chloride analysis; the assay may be reported separately.
82438 billing questions
When should this code be used instead of a blood or urine chloride code?
Use it for a chloride assay on a fluid source other than blood or urine. Blood and urine chloride assays have their own codes.
Can this code be used for sweat chloride testing?
Yes. Sweat chloride testing is an example of an other-fluid chloride assay and is used in cystic fibrosis evaluation.
Is sweat collection included in the assay?
The assay reports the chloride analysis. Sweat collection by iontophoresis may be reported with 89230 when that collection service is performed.
How many units should be reported?
Report the assay performed on the other-fluid specimen.
How does Medicare pay this test?
Medicare pays it through the CLFS at one national amount that applies across localities and in both office and facility settings. It is excluded from the physician fee schedule.
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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