Doctor profile · Federal record
Dr. Mark Fesler, MD
Hematology & Oncology Physician (CMS: Hematology/Oncology) · Internal Medicine Physician · Saint Louis, MO
- NPI 1235204066
- Accepts Medicare
- 23 yrs in practice
- Licensed in 2 states
- Male
- Group practice
- No sanctions
Practice & contact
- Primary practice
-
3655 Vista Ave
Saint Louis, MO 631102539
(314) 977-4340
fax (314) 773-1167
Credentials & registration
- NPI registered
- November 2006 — 20 yrs on file
- Profile last updated
- March 29, 2021
- Year of graduation
- 2003 — 23 yrs since
- Specialty taxonomy
- 207RH0003X — NUCC code
- State licenses (2)
- Missouri #2008029015 · Colorado #43133
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1235204066. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
1,150
Distinct HCPCS
4
Medicare allowed
$186,642
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99215 |
Established patient office or other outpatient visit, 40-54 minutes | 733 | 184 | $177 | |
99233 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 300 | 58 | $118 | |
99223 |
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 89 | 59 | $172 | |
99205 |
New patient office or other outpatient visit, 60-74 minutes | 28 | 28 | $217 |
In context: peer comparison
Among 12 peers in Saint Louis Hematology & Oncology Physician, average services per provider: 216. This provider delivers 5.3× the peer median.Open Payments
Industry payments received
All-time total
$192,797
Transactions
129
Manufacturers
15
| Payer (manufacturer) | Industry | Txns | Amount |
|---|---|---|---|
| Abbvie INC. | 28 | $40,500.71 | |
| Incyte Corporation | 24 | $36,349.69 | |
| Genzyme Corporation | 13 | $36,263.13 | |
| Genmab U.S., INC. | 12 | $22,719.62 | |
| Genentech USA, INC. | 14 | $20,817.85 | |
| Lilly USA, LLC | 13 | $17,870.35 | |
| BeiGene USA, INC. | 5 | $8,250.00 | |
| Adc Therapeutics America, INC. | 5 | $4,513.75 | |
| E.R. Squibb & Sons, L.L.C. | 1 | $2,768.00 | |
| AstraZeneca Pharmaceuticals Lp | 1 | $2,397.50 | |
| Novartis Pharmaceuticals Corporation | 4 | $82.35 | |
| Celgene Corporation | 4 | $76.25 | |
| Janssen Biotech, INC. | 2 | $48.73 | |
| Daiichi Sankyo INC. | 2 | $38.04 | |
| Takeda Pharmaceuticals U.S.A., INC. | 1 | $23.10 |
By nature of payment
Medicare Part D · 2023
Top prescriptions
Total claims
1,305
Patients
305
Total drug cost
$4,947,495
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Valacyclovir (Valacyclovir Hcl) | Brand | 266 | 61 | $15,714 |
| Acyclovir | Generic | 146 | 34 | $3,185 |
| Revlimid (Lenalidomide) | Brand | 144 | 18 | $3,003,123 |
| Sulfamethoxazole-Trimethoprim (Sulfamethoxazole/Trimethoprim) | Brand | 103 | 25 | $757 |
| Prednisone | Generic | 97 | 32 | $434 |
| Venclexta (Venetoclax) | Brand | 89 | 18 | $676,397 |
| Eliquis (Apixaban) | Brand | 74 | 14 | $61,922 |
| Levofloxacin | Generic | 73 | 23 | $1,089 |
| Dexamethasone | Generic | 57 | 17 | $861 |
| Hydroxyurea | Generic | 51 | 16 | $2,225 |
Frequently asked questions
What is Dr. Mark Fesler's medical specialty?
Dr. Mark Fesler practices Hematology & Oncology Physician in Saint Louis, MO.
Where does Dr. Mark Fesler practice?
Dr. Mark Fesler practices at 3655 Vista Ave, Saint Louis, MO 631102539. Office phone: 3149774340.
What is Dr. Mark Fesler's NPI?
Dr. Mark Fesler's National Provider Identifier (NPI) is 1235204066, issued by NPPES.
Does Dr. Mark Fesler accept Medicare assignment?
Yes. Dr. Mark Fesler accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark Fesler commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99215); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.