CPT code 82820: Oxygen affinity, P50 measurement2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures hemoglobin’s oxygen affinity by identifying the oxygen pressure at 50% saturation, including in evaluations of unexplained erythrocytosis.
Medicare pays $13.34 for 82820 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
$13.34
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 7 sections
What 82820 covers
82820 identifies a measurement of hemoglobin’s oxygen affinity, expressed as the oxygen partial pressure at which hemoglobin is 50% saturated (P50). It characterizes oxygen binding rather than reporting blood pH, a combination of blood-gas values, or oxygen saturation alone. Clinicians may use the result when evaluating unexplained erythrocytosis or suspected high-affinity hemoglobin, where altered oxygen binding can affect the body’s red-cell response. The result gives the ordering clinician information about hemoglobin’s oxygen-binding behavior; it is distinct from a routine oxygen-saturation value.
Report 82820 for the hemoglobin-oxygen affinity measurement. Medicare pays the test through the CLFS at one national amount across states and localities, without geographic or office/facility adjustment. The 2026 national amount is $13.34, unchanged from 2020 through 2026. The test is paid only through the CLFS and 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 82820
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 82820. 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 82820 with status X (excluded by statute), so the test itself is paid only from the CLFS.
82820 on the lab fee schedule since 2020
82820 · CLFS 2026 Q4 (current)
$13.34
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.
82820 compared with similar tests
- 82810Blood saturationOxygen saturation only$9.77
- 82810 represents blood-gas oxygen saturation only. Use 82820 for the hemoglobin oxygen-affinity measurement, not merely a saturation result.
- 82803Blood gasesCalculated oxygen saturation$26.07
- 82803 represents blood gases in any combination. 82820 is the specific hemoglobin-oxygen affinity measurement.
- 82800Blood pHpH only$11.00
- 82800 represents blood pH. 82820 measures hemoglobin’s oxygen affinity as the oxygen pressure at 50% saturation.
82820 billing questions
What does 82820 measure?
It measures hemoglobin’s oxygen affinity as the oxygen pressure at 50% hemoglobin saturation, or P50. It is not an oxygen-saturation-only result.
How is 82820 different from 82810?
82820 measures hemoglobin’s oxygen-binding affinity. 82810 represents blood-gas oxygen saturation only.
How is 82820 different from 82803?
82803 represents blood gases in any combination. 82820 identifies the specific hemoglobin-oxygen affinity measurement.
Does Medicare pay 82820 under the physician fee schedule?
No. Medicare pays 82820 through the CLFS; 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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