Doctor profile · Federal record
Dr. Gregory Warren, MD
Nephrology Physician · Milwaukee, WI
- NPI 1649262544
- 21 yrs on file
- Male
- Solo practice
- No sanctions
Practice & contact
- Primary practice
-
3120 South 27Th Street
Milwaukee, WI 53215
(414) 672-8282
fax (414) 672-8284 - Mailing address
-
335 Mahn Court
Oak Creek, WI 53154
Credentials & registration
- NPI registered
- August 2005 — 21 yrs on file
- Profile last updated
- December 9, 2021
- Specialty taxonomy
- 207RN0300X — NUCC code
- State license (1)
- Wisconsin #26514
- Medicaid
- WI #3082990
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1649262544. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
2,108
Distinct HCPCS
9
Medicare allowed
$275,561
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99233 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 704 | 193 | $108 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 338 | 185 | $117 | |
99232 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 314 | 141 | $73 | |
90935 |
Hemodialysis procedure with physician evaluation | 290 | 95 | $66 | |
90960 |
Dialysis services, 4 or more physician visits per month (20 years or older) | 278 | 31 | $333 | |
99223 |
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 78 | 72 | $161 | |
90947 |
Dialysis procedure requiring repeat evaluation | 67 | 26 | $115 | |
99222 |
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | 25 | 25 | $117 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 14 | 14 | $156 |
In context: peer comparison
Among 22 peers in Milwaukee Nephrology Physician, average services per provider: 129. This provider delivers 16× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
1,506
Patients
454
Total drug cost
$316,269
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Calcitriol | Generic | 220 | 61 | $3,184 |
| Furosemide | Generic | 180 | 56 | $1,798 |
| Losartan Potassium | Generic | 151 | 44 | $2,484 |
| Jardiance (Empagliflozin) | Brand | 138 | 38 | $183,598 |
| Terazosin Hcl | Generic | 130 | 49 | $3,880 |
| Amlodipine Besylate | Generic | 122 | 46 | $882 |
| Vitamin D2 (Ergocalciferol (Vitamin D2)) | Brand | 90 | 34 | $786 |
| Sevelamer Carbonate | Generic | 76 | 19 | $35,718 |
| Allopurinol | Generic | 72 | 24 | $1,640 |
| Hydrochlorothiazide | Generic | 66 | 20 | $374 |
Frequently asked questions
What is Dr. Gregory Warren's medical specialty?
Dr. Gregory Warren practices Nephrology Physician in Milwaukee, WI.
Where does Dr. Gregory Warren practice?
Dr. Gregory Warren practices at 3120 South 27Th Street, Milwaukee, WI 53215. Office phone: 4146728282.
What is Dr. Gregory Warren's NPI?
Dr. Gregory Warren's National Provider Identifier (NPI) is 1649262544, issued by NPPES.
What procedures does Dr. Gregory Warren commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Established patient office or other outpatient visit (HCPCS 99214); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232). Source: CMS Medicare Physician & Other Practitioners file.