CPT code 83550: Iron binding, binding capacity2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures the blood’s capacity to bind iron, typically as part of an iron study evaluating anemia, suspected iron deficiency, or iron overload.
Medicare pays $8.74 for 83550 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
$8.74
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 83550 covers
This laboratory test measures the blood’s capacity to bind iron, chiefly reflecting the iron-binding capacity of transferrin. It is commonly performed on a serum specimen and ordered during evaluation of anemia or suspected iron deficiency or iron overload. A clinician may interpret the result alongside serum iron and ferritin; the iron result and binding capacity can also be used to calculate transferrin saturation. Hospital and independent laboratories perform the assay for outpatient and inpatient orders.
Report 83550 for each iron-binding-capacity test performed. It is commonly paired with the serum iron assay, code 83540, as part of an iron study. Medicare pays it only under the CLFS, with one national amount across localities and no office-versus-facility difference. The 2026 national CLFS amount is $8.74, unchanged from 2020 through 2026. The test is paid through the CLFS rather than 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 83550
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 83550. 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 83550 with status X (excluded by statute), so the test itself is paid only from the CLFS.
83550 on the lab fee schedule since 2020
83550 · CLFS 2026 Q4 (current)
$8.74
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.
83550 compared with similar tests
- 83540Iron assaySerum iron concentration$6.47
- Use 83540 for the iron assay itself. Use 83550 for iron-binding capacity; report both when both are performed.
- 82728FerritinBlood ferritin level$13.63
- 82728 measures ferritin, a marker of stored iron. It does not measure iron-binding capacity.
- 84466TransferrinIron-binding protein level$12.76
- 84466 measures transferrin. Choose it when that protein is directly assayed rather than reporting an iron-binding-capacity test.
83550 billing questions
How is 83550 different from 83540?
83550 measures iron-binding capacity; 83540 measures iron in the specimen. They assess different parts of an iron study and are commonly reported together when both tests are performed.
Can 83550 be reported with ferritin?
Yes, when ferritin is separately ordered and performed as part of the patient’s iron evaluation. Report the ferritin test separately.
Does Medicare pay 83550 under the physician fee schedule?
No. Medicare pays 83550 through the CLFS, at one national amount regardless of locality or office versus facility setting.
How many units should be reported?
Report one unit for each iron-binding-capacity test performed; do not calculate units from the measured capacity or a calculated transferrin saturation.
Is a separate physician interpretation billed with 83550?
83550 is paid through the CLFS. The physician fee schedule does not provide payment for this test.
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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