Doctor profile · Federal record
Dr. Frederick Stack, MD
Internal Medicine Physician (CMS: Hospitalist) · Internal Medicine Physician · Specialist · Sioux City, IA
- NPI 1548256977
- Accepts Medicare
- 35 yrs in practice
- Licensed in 3 states
- Male
- Solo practice
- No sanctions
Practice & contact
Operates at 4 locations .
- Primary practice
-
801 5Th St
Sioux City, IA 511011326
(712) 279-2010
fax (712) 279-2034 - Additional location
-
1821 N Trekell RD, Suite 6
Casa Grande, AZ 852221705
(520) 421-1122
fax (520) 421-0751 - Additional location
-
1 Medical Center Dr
Biddeford, ME 040059422
(207) 283-7937 - Additional location
-
1101 26Th St S
Great Falls, MT 594055161
(406) 455-4694
fax (406) 731-8318 - Mailing address
-
6909 East Ray Road #15-114
Chandler, AZ 85226
Show 1 more location
Credentials & registration
- NPI registered
- September 2005 — 21 yrs on file
- Profile last updated
- January 28, 2026
- Year of graduation
- 1991 — 35 yrs since
- Specialty taxonomy
- 207R00000X — NUCC code
- State licenses (3)
- Iowa #MD-46368 · Montana #91977 · Arizona #24459
- Medicaid
- AZ #436693002
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1548256977. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
822
Distinct HCPCS
5
Medicare allowed
$72,115
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99232 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 609 | 189 | $76 | |
99239 |
Hospital discharge day management, more than 30 minutes | 131 | 129 | $110 | |
99222 |
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | 45 | 44 | $126 | |
99223 |
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 23 | 22 | $165 | |
99233 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes | 14 | 12 | $114 |
In context: peer comparison
Among 7 peers in this city , average services per provider: 108. This provider delivers 7.6× the peer median.Medicare Part D · 2023
Top prescriptions
Total claims
134
Patients
51
Total drug cost
$2,002
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Cefdinir | Generic | 23 | 23 | $382 |
| Pantoprazole Sodium | Generic | 17 | 13 | $213 |
| Amlodipine Besylate | Generic | 16 | 0 | $21 |
| Prednisone | Generic | 16 | 15 | $66 |
| Atorvastatin Calcium | Generic | 15 | 0 | $237 |
| Ezetimibe | Generic | 14 | 0 | $739 |
| Clopidogrel (Clopidogrel Bisulfate) | Brand | 11 | 0 | $238 |
| Lisinopril | Generic | 11 | 0 | $47 |
| Metoprolol Tartrate | Generic | 11 | 0 | $58 |
Frequently asked questions
What is Dr. Frederick Stack's medical specialty?
Dr. Frederick Stack practices Internal Medicine Physician in Sioux City, IA.
Where does Dr. Frederick Stack practice?
Dr. Frederick Stack practices at 801 5Th St, Sioux City, IA 511011326. Office phone: 7122792010.
What is Dr. Frederick Stack's NPI?
Dr. Frederick Stack's National Provider Identifier (NPI) is 1548256977, issued by NPPES.
Does Dr. Frederick Stack accept Medicare assignment?
Yes. Dr. Frederick Stack accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Frederick Stack commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Hospital discharge day management (HCPCS 99239); Initial hospital care with straightforward or low-level medical decision making (HCPCS 99222). Source: CMS Medicare Physician & Other Practitioners file.