CPT code 84203: RBC protoporphyrin, screening test2026 Medicare lab fee · Clinical Laboratory Fee Schedule
This code reports a screening test for protoporphyrin in red blood cells, distinct from the red blood cell protoporphyrin assay reported with 84202.
Medicare pays $9.74 for 84203 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
$9.74
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 84203 covers
Code 84203 identifies a screening test for protoporphyrin in red blood cells. It is distinct from 84202, which identifies the red blood cell protoporphyrin assay. Choose between these codes according to whether the service performed is the screening test or the assay; the shared analyte does not make the services interchangeable. Report 84203 when the service performed is the screening test, not the assay.
Medicare pays 84203 through the CLFS. For 2026, its national amount is $9.74, unchanged from 2020 through 2026. The same CLFS amount applies across states and localities, with no geographic or office-versus-facility adjustment. The physician fee schedule excludes the test by statute, so Medicare payment is 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 84203
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 84203. 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 84203 with status X (excluded by statute), so the test itself is paid only from the CLFS.
84203 on the lab fee schedule since 2020
84203 · CLFS 2026 Q4 (current)
$9.74
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.
84203 compared with similar tests
- 84202Red-cell protoporphyrinQuantitative assay$14.35
- 84203 identifies a red blood cell protoporphyrin screening test; 84202 identifies the assay.
- 83655Lead testBlood lead level$12.11
- 83655 measures blood lead, while 84203 screens for protoporphyrin in red blood cells.
- 83540Iron assaySerum iron concentration$6.47
- 83540 measures iron; 84203 screens for protoporphyrin in red blood cells.
84203 billing questions
When should 84203 be selected instead of 84202?
Use 84203 for the red blood cell protoporphyrin screening service. Use 84202 for the assay service.
What does 84203 screen for?
It screens for protoporphyrin in red blood cells.
Is modifier 26 appropriate for 84203?
No. Medicare pays 84203 only through the CLFS; the physician fee schedule excludes the test by statute.
Does Medicare payment vary by locality or setting?
No. The CLFS amount is the same across states and localities, with no geographic or office-versus-facility adjustment.
Is 84203 an assay code?
No. It identifies the screening service; 84202 identifies the red blood cell protoporphyrin assay.
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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