CPT code 85004: WBC differential, automated count2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Reports an automated differential of white blood cells in a blood specimen when the differential is performed without billing a complete CBC with automated differential.
Medicare pays $6.47 for 85004 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
$6.47
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 85004 covers
This test uses an automated hematology analyzer to determine the distribution of white blood cell types in a blood specimen. The differential helps clinicians assess changes in leukocyte populations in situations such as suspected infection, inflammation, or hematologic disease. Clinical laboratories commonly perform it for outpatient practices and other settings that order blood counts.
Report 85004 for the automated differential itself, rather than for a complete blood count that includes an automated differential. When a complete CBC with automated differential is performed, 85025 represents that broader service. Medicare pays 85004 only through the CLFS. The 2026 national CLFS amount is $6.47, unchanged from 2020 through 2026; one amount applies nationwide, without locality or office-versus-facility adjustment. The test has no separate 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 85004
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 85004. 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 85004 with status X (excluded by statute), so the test itself is paid only from the CLFS.
85004 on the lab fee schedule since 2020
85004 · CLFS 2026 Q4 (current)
$6.47
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.
85004 compared with similar tests
- 85025Complete CBCAutomated differential$7.77
- 85025 represents a complete CBC with an automated differential. 85004 represents the automated differential without the complete CBC service.
- 85007Manual differentialMicroscopic white cell count$3.80
- Use 85007 when the differential is performed by examining a blood smear; 85004 is for an automated differential.
- 85048WBC countAutomated method$2.54
- 85048 reports an automated total leukocyte count. 85004 reports the distribution of white blood cell types.
- 85027Complete CBCWithout automated differential$6.47
- 85027 is an automated complete CBC without a differential. 85004 is the automated differential, not the complete CBC.
85004 billing questions
When should 85004 be used instead of 85025?
Use 85004 for an automated white blood cell differential alone. Use 85025 when the service is a complete CBC with an automated differential.
How does 85004 differ from 85048?
85004 reports the automated distribution of white blood cell types. 85048 reports an automated leukocyte count, not a differential.
What is the difference between 85004 and 85007?
85004 is for an automated differential. 85007 is for a differential performed by blood-smear examination.
What should the documentation support?
Documentation should identify the automated differential performed and distinguish it from a complete CBC or a total leukocyte count.
How does Medicare pay for 85004?
Medicare pays the test through the CLFS at one national amount, with no locality or office-versus-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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