Medicare Enrolled
Dr. Thomas Ahn, MD
Internal Medicine · Los Angeles, CA
Practice pattern: Mixed Practice
— Diverse clinical practice across multiple procedure types
Very High
DATA COVERAGE
Data in 4 of 4 federal sources
Measures public federal data availability — not provider quality
Informational, not a quality rating.
This page presents federal public records about Dr. Ahn from CMS (NPPES, Open Payments, Medicare Provider Utilization, PECOS). It is not medical advice, an endorsement, or a judgment of clinical quality. Always consult the provider directly and a licensed clinician for medical decisions. Read methodology →
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What this data tells you about Dr. Ahn
Dr. Thomas Ahn is an internal medicine specialist in Los Angeles, CA, with 19 years of NPI registration. Based on federal Medicare data, Dr. Ahn performed 9,443 Medicare services in 2023. These records do not provide a deduplicated patient total.
Between the years covered by Open Payments, Dr. Ahn received a total of $14,613 from 64 pharmaceutical and/or device companies across 722 payment records. A record can group multiple payments. These transfers are publicly reported through CMS Open Payments. Disclosure alone does not establish their effect on care. A reliable breakdown by payment category is not available in this snapshot. Patients may wish to discuss these relationships with their provider.
The Data Coverage level for Dr. Ahn is Very High — reflecting how much public federal data is available about this provider. Patients are encouraged to use this data as one of several factors when choosing a healthcare provider.
✓ 19 years of NPI registration
▲ Top 3% volume in CA
$14,613 industry payments
Medicare Practice Summary — 2023
Medicare Utilization ↗9,443
Medicare services
Top 3% in CA for internal medicine
Not available
Unique patients (not deduplicated)
$19
Avg. Medicare payment
Medicare patients only (65+ / disabled) · How to read this →
Top procedures by volume
Ranked by number of services performed for Medicare patients. Avg. submitted charge is what the provider billed; avg. Medicare payment is what CMS paid.
| Procedure | Volume | Avg. paid | Avg. submitted |
|---|---|---|---|
| Thyroid stimulating hormone (TSH) test A blood test that measures the level of thyroid stimulating hormone to evaluate thyroid function. |
590 | $16 | $50 |
| Uric acid level test A blood test that measures the level of uric acid in your body. Uric acid is a waste product formed when the body breaks down purines. |
580 | $4 | $12 |
| Lactate dehydrogenase (LDH) level test A blood test that measures the amount of lactate dehydrogenase, an enzyme found in many body tissues. It helps assess tissue damage or disease. |
576 | $6 | $12 |
| Comprehensive metabolic blood panel A blood test that measures a group of chemicals, including glucose, electrolytes, and kidney and liver function markers. |
575 | $10 | $75 |
| Free thyroxine (T4) test A blood test that measures the level of free thyroxine, a thyroid hormone, in the bloodstream. |
566 | $9 | $50 |
| Lipid panel (cholesterol and triglycerides) A blood test that measures cholesterol and triglyceride levels. |
556 | $13 | $75 |
| Glutamyltransferase (GGT) level test A blood test that measures the level of the liver enzyme glutamyltransferase (GGT) to help evaluate liver health. |
551 | $7 | $22 |
| Complete blood count (CBC) with differential An automated laboratory test that measures the levels of red blood cells, white blood cells, and platelets in the blood, including a breakdown of the different types of white blood cells. |
542 | $8 | $28 |
| Vitamin D level test A blood test to measure the amount of Vitamin D-3 in your body. |
517 | $29 | $45 |
| Phosphate level test A blood test that measures the amount of phosphate in your body. Phosphate is a mineral that helps keep bones and teeth strong. |
495 | $5 | $12 |
| Erythrocyte sedimentation rate (ESR) test A blood test that measures how quickly red blood cells settle in a test tube to detect inflammation in the body. This specific method is performed manually rather than using an automated machine. |
479 | $4 | $20 |
| Hemoglobin A1c test (diabetes monitoring) A blood test that measures your average blood sugar levels over the past two to three months. |
460 | $9 | $40 |
| Vitamin B-12 unsaturated binding capacity test A blood test that measures the unsaturated binding capacity of vitamin B-12. This procedure assesses the amount of vitamin B-12 binding protein available in the blood. |
446 | $14 | $54 |
| Blood draw (venipuncture) Insertion of a needle into a vein to collect a blood sample. |
355 | $8 | $30 |
| Venipuncture for blood draw Insertion of a needle into a vein to collect blood samples. This procedure is performed on patients aged 3 years or older. |
324 | $13 | $30 |
| Office visit, established patient (20-29 min) An office visit for an existing patient lasting between 20 and 29 minutes. The visit involves medical evaluation and management of the patient's condition. |
291 | $71 | $130 |
| Office visit, established patient, complex (40-54 min) An office or outpatient visit for an existing patient lasting between 40 and 54 minutes. This level of service is determined by the total time spent on the date of the encounter. |
276 | $131 | $220 |
| Office visit, established patient (30-39 min) A follow-up office visit for an existing patient lasting between 30 and 39 minutes. The visit involves medical evaluation and management of the patient's condition. |
224 | $95 | $175 |
| Electrocardiogram (EKG), 12-lead A standard heart rhythm test using at least 12 leads to record electrical activity. A healthcare provider interprets the results and provides a written report. |
221 | $11 | $65 |
| PSA test (prostate cancer screening) | 218 | $18 | $55 |
| Stool test for blood to screen for colon tumors A test that analyzes a stool sample to detect hidden blood, which is used to screen for colon tumors. |
153 | $4 | $20 |
| Drug injection, under skin or into muscle A procedure involving the administration of a medication or substance via injection into the subcutaneous tissue or muscle. |
106 | $11 | $35 |
| Office visit, established patient (10-19 min) An office visit for an existing patient lasting 10 to 19 minutes. The visit involves medical evaluation and management of the patient's condition. |
90 | $41 | $100 |
| Urinalysis, microscopic examination A laboratory test that examines a urine sample under a microscope to check for cells, crystals, bacteria, or other substances. |
68 | $3 | $10 |
| Continuous glucose monitoring with interpretation This procedure involves monitoring blood sugar levels in tissue fluid using a sensor placed under the skin, along with the interpretation and reporting of the results. |
41 | $28 | $75 |
| New patient office visit (45-59 min) An initial office visit for a new patient lasting between 45 and 59 minutes. This code covers the total time spent by the physician or qualified healthcare professional on the date of the encounter. |
36 | $112 | $219 |
| Total testosterone level test A blood test that measures the total amount of testosterone in your body. This hormone is important for various bodily functions in both men and women. |
30 | $25 | $85 |
| Free T3 thyroid hormone test A blood test that measures the level of free triiodothyronine (T3) hormone in your body. This helps assess how well your thyroid gland is functioning. |
20 | $17 | $75 |
| High-sensitivity C-reactive protein test A blood test that measures high-sensitivity C-reactive protein to detect infection or inflammation. |
19 | $13 | $25 |
| Continuous glucose monitoring, sensor under skin This procedure involves continuous monitoring of blood sugar levels in tissue fluid using a sensor placed under the skin with provider-supplied equipment. |
15 | $136 | $200 |
| Lipase level test A blood test that measures the amount of lipase, a fat-digesting enzyme, in your body. |
12 | $7 | $20 |
| New patient office visit, complex (60-74 min) | 11 | $171 | $259 |
How to read this data: This reflects Medicare patients only (typically 65+). Payment amounts are what Medicare paid the provider, not your out-of-pocket cost. These counts do not measure clinical quality or years of experience.
Industry Payment Transparency
Open Payments through 2024 ↗$14,613
Total received (2018-2024)
Avg $2,088/year across 7 years
Top 7% in CA for internal medicine
A higher payment rank reflects disclosed industry relationships (consulting, research, speaking) common among subspecialists — not wrongdoing.
64
Companies
722
Payment records
Payments are publicly reported; disclosure does not establish legality · Not evidence of wrongdoing · How to interpret →
Payment categories are unavailable while the source breakdown is being rebuilt. Company and year totals do not identify how much belongs to each category.
Payment trend by year
Annual totals from pharmaceutical and medical device companies.
2024
$2,596
2023
$2,549
2022
$1,862
2021
$2,092
2020
$1,520
2019
$2,146
2018
$1,848
Payments by company (2024)
ABBVIE INC.
$416
Lilly USA, LLC
$404
Novo Nordisk Inc
$220
AstraZeneca Pharmaceuticals LP
$188
Mannkind Corporation
$176
Bayer Healthcare Pharmaceuticals Inc.
$174
Dexcom, Inc.
$153
Abbott Laboratories
$114
Amgen Inc.
$109
PFIZER INC.
$99
Tandem Diabetes Care, Inc.
$87
Madrigal Pharmaceuticals
$78
Radius Health, Inc.
$77
IBSA Pharma Inc.
$65
Novartis Pharmaceuticals Corporation
$64
Ceribell, Inc.
$32
Mallinckrodt Hospital Products Inc.
$28
Ardelyx, Inc.
$28
Boehringer Ingelheim Pharmaceuticals, Inc.
$24
BETA BIONICS, INC.
$23
GlaxoSmithKline, LLC.
$18
ACADIA Pharmaceuticals Inc
$17
Top 3 companies account for 40.1% of 2024 payments
All-time payments by company (2018-2024) ›
Lilly USA, LLC
$1,747
Amgen Inc.
$1,708
SANOFI-AVENTIS U.S. LLC
$1,294
AbbVie Inc.
$1,057
Novo Nordisk Inc
$987
ABBVIE INC.
$776
AstraZeneca Pharmaceuticals LP
$692
Boehringer Ingelheim Pharmaceuticals, Inc.
$557
AbbVie, Inc.
$385
IBSA Pharma Inc.
$354
Bayer Healthcare Pharmaceuticals Inc.
$323
Merck Sharp & Dohme Corporation
$280
Mannkind Corporation
$270
Horizon Therapeutics plc
$257
Dexcom, Inc.
$252
MannKind Corporation
$209
Abbott Laboratories
$204
PFIZER INC.
$201
Amarin Pharma Inc.
$182
ARBOR PHARMACEUTICALS, INC.
$154
Zealand Pharma US, Inc.
$150
Bayer HealthCare Pharmaceuticals Inc.
$137
Allergan, Inc.
$135
Eisai Inc.
$135
Antares Pharma, Inc.
$127
Otsuka America Pharmaceutical, Inc.
$123
Novartis Pharmaceuticals Corporation
$108
Mallinckrodt Hospital Products Inc.
$97
Supernus Pharmaceuticals, Inc.
$93
bioMerieux Inc
$90
Medtronic, Inc.
$89
Tandem Diabetes Care, Inc.
$87
Biohaven Pharmaceutical Holding Company Ltd.
$83
VistaPharm, Inc.
$81
Regeneron Healthcare Solutions, Inc.
$80
Madrigal Pharmaceuticals
$78
IDORSIA PHARMACEUTICALS US INC
$78
Radius Health, Inc.
$77
Relypsa, Inc.
$77
Kowa Pharmaceuticals America, Inc.
$68
Shire North American Group Inc
$65
Janssen Pharmaceuticals, Inc
$59
Ardelyx, Inc.
$57
Acerus Pharmaceuticals Corporation
$55
Takeda Pharmaceuticals U.S.A., Inc.
$51
DEXCOM, INC.
$39
Biohaven Pharmaceuticals, Inc.
$38
GlaxoSmithKline, LLC.
$38
Xeris Pharmaceuticals, Inc.
$35
Ceribell, Inc.
$32
GRT US Holding, Inc.
$28
IMPEL PHARMACEUTICALS INC.
$25
BETA BIONICS, INC.
$23
Ascensia Diabetes Care Us Inc.
$22
OPKO Pharmaceuticals, LLC
$21
SUN PHARMACEUTICAL INDUSTRIES INC.
$21
E.R. Squibb & Sons, L.L.C.
$19
Nalpropion Pharmaceuticals LLC
$19
ACADIA Pharmaceuticals Inc
$17
Becton, Dickinson and Company
$16
Alvogen Inc
$16
Dentsply Sirona Inc
$14
Medicure Pharma Inc.
$12
Azurity Pharmaceuticals, Inc.
$12
Top 3 companies account for 32.5% of all-time payments
Associated products mentioned in payments ›
ACCURIAN · ACTHAR · AFREZZA · AIRSUPRA · AREXVY · Aimovig · Androgel · BAQSIMI · BASAGLAR · BD Nano · BELSOMRA · BREZTRI · BYDUREON · COLOGUARD · COMIRNATY · CONTRAVE · CREON · Corlanor · DEXCOM CGM · DEXCOM G6 CGM SYSTEM · DEXCOM G6 TRANSMITTER · Dayvigo · Dexcom CGM · Dexcom G6 Transmitter · ELIQUIS · ETERNA · EVENITY · Edarbi · FARXIGA · FORTEO · FREESTYLE LIBRE · FREESTYLE LIBRE 2 · FREESTYLE LIBRE 3 · GVOKE PFS · HUMALOG · HUMULIN · IBSRELA · INPEN SMART INSULIN DELIVERY SYSTEM · INVOKANA · InPen · JANUVIA · JARDIANCE · JYNARQUE · KAPSPARGO · Kerendia · LANTUS · LEQVIO · LICART · LINZESS · LOKELMA · Livalo · MOUNJARO · MOVANTIK · NATPARA (PARATHYROID HORMONE) · NOCDURNA · NUPLAZID · NURTEC ODT · Natesto · Otezla · Otrexup · Ozempic · PAXLOVID · POCKET EEG DEVICE · PRALUENT · PRALUENT ALIROCUMAB INJECTION · Parsabiv · Prolia · QULIPTA · QUVIVIQ · Qutenza · RAYOS · RESMETIROM · Rayaldee · Repatha · Rybelsus · SOLIQUA · SOLIQUA 100/33 · SOMAVERT · STEGLATRO · SYMBICORT · SYNTHROID · Saxenda · Seglentis · Synthroid · TEPEZZA · TERIPARATIDE · TERLIVAZ · TOUJEO · TPH Spectra Universal Composite Restorative Low Viscosity · TRADJENTA · TRELEGY ELLIPTA · TRULICITY · Thyquidity · Tirosint · Tresiba · Trintellix · Trudhesa · UBRELVY · Vascepa · Veltassa · Victoza · Wegovy · XARELTO · XYOSTED · ZEGALOGUE · ZEPBOUND · ZYPITAMAG · iLet Bionic Pancreas · t:slim X2 Insulin Pump with Control-IQ
Should you be concerned? Industry payments are disclosed through CMS Open Payments. Disclosure alone does not establish their purpose, legality, or effect on care. What matters is whether a recommended drug or device appears in your doctor's payment records. If so, consider asking your doctor about it. How to interpret this data →
Geographic Context
Internal medicine physicians in nearby ZIP areas
4,722
County median income
$87,760
Nearest hospital to ZIP centroid (approximate)
KAISER FOUNDATION HOSPITAL - WEST LA
2.0 mi
2.0 mi
Data Sources
| Provider Registry | ✓ NPPES | NPPES snapshot; verify current record |
| Medicare Enrollment | ✓ PECOS | PECOS snapshot |
| Practice Data | ✓ Medicare Util. | Annual (CY lag) |
| Industry Payments | ✓ Open Payments | CY 2024 |
| Disciplinary History | — Not included | N/A |
This provider has data in 4 of 4 available federal datasets, with a Data Coverage level of Very High. This reflects how much public data is available about a provider. How we calculate this →
Summary
Dr. Ahn is a mixed practice specialist, with above-average Medicare volume (top 3% in CA), with 19 years of NPI registration.
This summary is auto-generated from federal data, describing data availability and patterns. Read our methodology →
Frequently Asked Questions
Is Dr. Ahn experienced with thyroid stimulating hormone (tsh) test?
Based on Medicare claims data, Dr. Ahn performed 590 thyroid stimulating hormone (tsh) test services. These records cover Medicare fee-for-service activity, including eligible younger beneficiaries; they do not measure total practice volume or clinical quality.
Does Dr. Ahn receive payments from pharmaceutical companies?
Yes. Dr. Ahn received a total of $14,613 from 64 companies across 722 payment records. A record can group multiple payments. These transfers are publicly disclosed through CMS Open Payments. Disclosure alone does not establish their legality or effect on care. Patients may wish to ask their doctor about these relationships, especially if a recommended drug or device appears in the payment records.
How do Dr. Ahn's costs compare to other internal medicine physicians in Los Angeles?
Dr. Ahn's average Medicare payment per service is $19. Note that these figures represent what Medicare pays, not your out-of-pocket cost, which depends on your specific insurance plan and deductible. Procedure-level data above shows both what was submitted and what Medicare paid for each service type.
What does Data Coverage mean?
Data Coverage (currently Very High for Dr. Ahn) measures how much public federal data is available about a provider. It is not a quality rating. A "Very High" or "High" level means the provider has data across multiple federal sources (NPPES, PECOS, Medicare Utilization, Open Payments), indicating the presence of registry, enrollment, activity or payment records, not verified experience or clinical quality. A "Low" or "Moderate" level may simply mean the provider is newer, does not see Medicare patients, or has not received any industry payments — none of which are inherently negative. Read our full methodology →
Is this data up to date?
Source publication dates and the snapshots loaded on this site can differ. Rebuilding a page does not refresh its source records. Check the Medicare reporting year and the payment interval shown above; consult the linked official sources for newer releases and current registry details. See our data freshness policy →
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About this page
This page combines public CMS records with calculated summaries and explanatory procedure labels. These transformations are not verbatim federal records. Sources: NPPES ↗, Open Payments ↗, Medicare Provider Utilization ↗, and PECOS. Publication is mandated by the Physician Payments Sunshine Act (§6002 ACA, 42 U.S.C. §1320a-7h) and the Freedom of Information Act.
This page is not medical advice, an endorsement, a recommendation, or a quality rating. Data Coverage reflects data completeness — how much federal information exists for this provider — not clinical performance, patient outcomes, or quality of care. Always verify information directly with the provider and consult a licensed clinician before making medical decisions.
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