Internal Medicine, Hematology & Oncology · Saint Louis, MO
NPI
1235204066
Since 2006
Specialty
Internal Medicine, Hematology & Oncology
Code 207RH0003X
Group practices
2
Medicare group memberships
Hospitals
1
Hospital affiliations
3655 Vista Ave
Saint Louis, MO, 63110
Phone (314) 977-4340
Groups this clinician bills Medicare through
Medicare paid, 2024
$195K
2,082 services
Medicare patients, 2024
258
Average age 77
Drug cost, 2024
$12.4M
2,654 prescriptions
Company payments, 2025
$197K
From 19 companies
Procedures and visits billed to Original Medicare, 2024
In 2024, the most common Medicare service billed by Mark J Fesler was code 99215 (office e&m - established), 864 times for 201 patients. In total Mark J Fesler billed 2,082 services in 16 codes, and Medicare paid $195K.
| Code |
|---|
Official US government data: the national provider registry and Medicare enrollment records, linked by NPI. Last update of this record: 2021-03-29.
| Setting |
|---|
| Services |
|---|
| Patients |
|---|
| Paid per service |
|---|
| Medicare paid |
|---|
| 99215 Office E&M - Established | Office | 864 | 201 | $130.81 | $113K |
| 99233 Hospital E&M - Subsequent | Facility | 421 | 70 | $90.03 | $38K |
| 99223 Hospital E&M - Initial | Facility | 124 | 77 | $131.52 | $16K |
| 99205 Office E&M - New | Office | 28 | 28 | $160.69 | $4,499 |
| 99214 Office E&M - Established | Office | 15 | 15 | $98.22 | $1,473 |
By year: 2022 $105K for 938 services; 2023 $146K for 1,186 services; 2024 $195K for 2,082 services.
Medicare prescription drug claims, 2024
In 2024, the drug Mark J Fesler prescribed most often to Medicare patients was Valacyclovir (Valacyclovir Hcl), with 355 prescriptions and refills. In total Mark J Fesler wrote 2,654 Medicare prescriptions that cost $12.4M.
| Drug | Claims | 30-day fills | Patients | Cost |
|---|---|---|---|---|
| Valacyclovir Valacyclovir Hcl | 355 | 681 | 85 | $15K |
| Revlimid Lenalidomide | 169 | 169 | 23 | $3.2M |
| Sulfamethoxazole-Trimethoprim Sulfamethoxazole/Trimethoprim | 165 | 268 | 42 | $1,073 |
| Acyclovir Generic | 162 | 289 | 36 | $2,157 |
| Venclexta Venetoclax | 159 | 162 | 32 | $1.2M |
| Lenalidomide Generic | 125 | 125 | 17 | $2.1M |
| Prednisone Generic | 115 | 126 | 31 | $459 |
| Dexamethasone Generic | 91 | 127 | 28 | $1,704 |
| Eliquis Apixaban | 87 | 117 | 15 | $67K |
| Levofloxacin Generic | 55 | 65 | 29 | $608 |
| Brukinsa Zanubrutinib | 53 | 53 | Under 11 | $738K |
| Ondansetron Hcl Generic | 50 | 50 | 33 | $488 |
| Posaconazole Generic | 46 | 46 | 12 | $92K |
| Potassium Chloride Generic | 43 | 73 | 17 | $1,265 |
| Oxycodone Hcl Generic | 43 | 43 | Under 11 | $694 |
Brand drugs: - claims; generic drugs: 1,861 claims; opioid claims: 64.
Money and other things of value reported by the companies
In 2025, drug and medical device companies paid Mark J Fesler $197K ($196K in general payments such as food, travel and fees and $1,147 for research) from 19 companies. The largest payer was Incyte Corporation with $47K.
| Company | Payments | Amount |
|---|---|---|
| Incyte Corporation INCY | 29 | $47K |
| Abbvie Inc. ABBV | 28 | $43K |
| Adc Therapeutics America, Inc. | 13 | $29K |
| BeOne Medicines USA, Inc. ONC | 10 | $20K |
| Genzyme Corporation SNY | 5 | $15K |
| Regeneron Healthcare Solutions, Inc. REGN | 5 | $12K |
| Lilly USA, LLC LLY | 7 | $9,509 |
| Genmab U.S., Inc. GMAB | 3 | $5,400 |
| AstraZeneca Pharmaceuticals LP AZN | 2 | $5,330 |
| Ipsen Biopharmaceuticals, Inc IPN.PA | 1 | $4,410 |
Official US government data on Original Medicare services, Medicare prescription drug plans and the payments drug and device companies must report. Services with fewer than 11 patients and drugs with fewer than 11 claims are not published. Procedure codes are shown by number with their public category.