Doctor profile · Federal record
Dr. Timothy Wassenaar, MD
Hematology & Oncology Physician (CMS: Hematology/Oncology) · Internal Medicine Physician · Waukesha, WI
- NPI 1518928993
- Accepts Medicare
- 24 yrs in practice
- Male
- Group practice
- No sanctions
Practice & contact
- Primary practice
-
N16W24131 Riverwood Dr
Waukesha, WI 531881106
(262) 696-5690
Credentials & registration
- NPI registered
- March 2006 — 20 yrs on file
- Profile last updated
- January 10, 2024
- Year of graduation
- 2002 — 24 yrs since
- Specialty taxonomy
- 207RH0003X — NUCC code
- State license (1)
- Wisconsin #46327
- Medicaid
- WI #34691700
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1518928993. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
702
Distinct HCPCS
9
Medicare allowed
$77,010
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 160 | 119 | $92 | |
99215 |
Established patient office or other outpatient visit, 40-54 minutes | 153 | 95 | $135 | |
99233 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 124 | 62 | $112 | |
99232 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 79 | 33 | $74 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 66 | 43 | $92 | |
99205 |
New patient office or other outpatient visit, 60-74 minutes | 47 | 47 | $169 | |
99215 |
Established patient office or other outpatient visit, 40-54 minutes | 42 | 29 | $135 | |
G0316 |
Prolonged hospital inpatient or observation care evaluation and management service(s) beyond the total time for the primary service (when the primary service has been selected using time on the date of the primary service); each additional 15 minutes by th | 20 | 19 | $29 | |
99223 |
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 11 | 11 | $163 |
In context: peer comparison
Among 2 peers in this city , average services per provider: 82. This provider delivers 8.6× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
945
Patients
172
Total drug cost
$2,589,336
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Acyclovir | Generic | 181 | 41 | $3,767 |
| Hydroxyurea | Generic | 125 | 26 | $4,618 |
| Eliquis (Apixaban) | Brand | 106 | 19 | $107,225 |
| Warfarin Sodium | Generic | 81 | 14 | $1,079 |
| Imbruvica (Ibrutinib) | Brand | 70 | 0 | $1,077,790 |
| Xarelto (Rivaroxaban) | Brand | 47 | 12 | $49,500 |
| Famotidine | Generic | 45 | 0 | $232 |
| Imatinib Mesylate | Generic | 44 | 0 | $57,313 |
| Potassium Chloride | Generic | 38 | 0 | $884 |
| Sulfamethoxazole-Trimethoprim (Sulfamethoxazole/Trimethoprim) | Brand | 38 | 18 | $287 |
Hospital affiliations
Frequently asked questions
What is Dr. Timothy Wassenaar's medical specialty?
Dr. Timothy Wassenaar practices Hematology & Oncology Physician in Waukesha, WI.
Where does Dr. Timothy Wassenaar practice?
Dr. Timothy Wassenaar practices at N16W24131 Riverwood Dr, Waukesha, WI 531881106. Office phone: 2626965690.
What is Dr. Timothy Wassenaar's NPI?
Dr. Timothy Wassenaar's National Provider Identifier (NPI) is 1518928993, issued by NPPES.
Does Dr. Timothy Wassenaar accept Medicare assignment?
Yes. Dr. Timothy Wassenaar accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Timothy Wassenaar commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Established patient office or other outpatient visit (HCPCS 99215); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233). Source: CMS Medicare Physician & Other Practitioners file.