- Market sizeThe volume of this code in the market for the year: an all-Medicare estimate scaled from the observed fee-for-service count where one can be drawn, otherwise the narrower count the row names. ~18,477 all-Medicare services · est. (9,107 observed FFS). The #1 state market of 50 by est. all-Medicare volume.
- Billing groupsHow many named billing organizations billed this code in the market, and the services they billed between them. Billing that falls under CMS's 11-beneficiary disclosure floor is absent from the published record. 21 groups bill G0399 in California — 2,684 observed fee-for-service services (at the ≥11-beneficiary disclosure floor).
- GrowthHow this code's volume changed year over year and over five years. A change between two years of the record, never a projection of what comes next. Down 6.9% year over year; -7.0% over five years, #32 of 49 by five-year growth.
- Market structureHow much of the state's named-group volume the five largest billing groups hold, banded: under 40% fragmented, 40–60% moderately concentrated, 60–80% concentrated, 80%+ highly concentrated. Our bands, not a regulator's. Not shown for markets under 11 billing groups, or where named groups cover under 25% of the state's disclosed volume — both published floors. Concentrated — 21 billing groups, the top five holding 64% of named-group volume.
- Concentration trendHow the five largest groups' share of this market moved between the two years shown. An endpoint comparison on the group roster, not a reading of every year in between. Less concentrated in 2024 than 2022 (top 5 hold 66% → 64%, group-roster grain).
- Medicare paymentWhat Medicare paid for this code in the market over the year, and the payment per service. Observed fee-for-service payments only: Medicare Advantage is paid by capitation and is not counted.Medicare's payments for G0399 in California in 2024, and this market's payment per service against the national rate. Explore — see what Medicare pays for this →
This market's Overview — its estimated all-Medicare volume, national benchmarks, and what the field charges and is paid — is part of Explore.
The groups in this market that bill this code, ranked by volume, are part of a Deep Dive.
The clinicians in this market who bill this code, ranked by volume, are part of a Deep Dive.
The codes the same organizations bill alongside this one are part of a Deep Dive.
G0399 is not priced under the Physician Fee Schedule, so there is no schedule rate to compare against. Codes that pay similarly cannot be listed.
More than 200 groups billed G0399 in 2024, so no comparison is drawn: this read is for codes with thin adoption, where a same-state comparison set is small enough to be a comparison rather than a census. The Provider groups tab lists the billers.
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