CPT code 83861: Tear osmolarity, microfluidic measurement2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Microfluidic tear osmolarity testing measures tear concentration and is reported when an eye-care clinician assesses or monitors dry eye disease.
Medicare pays $22.48 for 83861 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
$22.48
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
- $22.48
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 83861 covers
Code 83861 represents microfluidic measurement of tear osmolarity using a device that collects and analyzes a tear sample. Ophthalmologists and optometrists use the result when evaluating symptoms or signs of dry eye disease and assessing the ocular surface. This measurement supports dry eye assessment and differs from a tear inflammatory-marker assay.
Report 83861 for the tear osmolarity test performed. CMS lists a QW version for sites with a CLIA certificate of waiver. Medicare pays this test only under the CLFS, at one national amount across states and localities, without geographic or office/facility adjustment. The 2026 national amount is $22.48, unchanged from 2020 through 2026; the test has no physician fee schedule payment.
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 83861
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 83861. 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 83861 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 83861 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $22.48.
83861 on the lab fee schedule since 2020
83861 · CLFS 2026 Q4 (current)
$22.48
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.
83861 compared with similar tests
- 83516ImmunoassayMultiple-step, qualitative or semiquantitative$11.53
- Choose 83861 for microfluidic measurement of tear osmolarity. Code 83516 is an immunoassay, including tear inflammatory-marker testing.
83861 billing questions
When should this code be selected?
Use 83861 for microfluidic measurement of tear osmolarity when assessing dry eye disease. It is distinct from tear inflammatory-marker testing.
When is modifier QW appropriate?
CMS lists a CLIA-waived version with QW. The waiver version is for sites holding a CLIA certificate of waiver.
What does the test measure?
It measures tear osmolarity from a tear sample using a device that collects and analyzes the sample.
How does this differ from code 83516?
Code 83861 measures tear osmolarity. Code 83516 represents an immunoassay, including tear inflammatory-marker testing.
Does Medicare payment vary by location or setting?
No. The CLFS amount is national and applies across localities, without 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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