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DR. FREDERICK RICHARD STACK MD
NPI 1548256977
Internal Medicine in Sioux City, IA

Active since September 21, 2005PECOS EnrolledAccepts Medicare Assignment
801 5TH ST, SIOUX CITY, IA 51101(712) 279-2010(712) 279-2034 Get Directions Write a Review

NPPES record last updated: January 28, 2026. Verified against the NPPES registry weekly; last sync: September 06, 2026.

Record update history: Jan 28, 2026, Jul 10, 2023, Dec 22, 2020 and 1 more (4 updates tracked since 2019).

About Dr. Frederick Richard Stack Md NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. FREDERICK RICHARD STACK MD (NPI 1548256977) is an individual internal medicine provider in Sioux City, Iowa, licensed in Iowa (MD-46368) and active in the NPI registry since September 2005. He is enrolled in Medicare PECOS, is affiliated with Cary Medical Center, and maintains 3 additional practice locations.

NPPES Registry Identity

NPI1548256977
Entity TypeIndividualMale
Primary Taxonomy207R00000X
Provider Legal NameDR. FREDERICK RICHARD STACKCredential: MD
Location Address801 5TH STSioux City, IA 51101-1326
Mailing Address6909 East Ray Road #15-114Chandler, AZ 85226 · (520) 421-1122 · Fax (520) 421-0751
Phone(712) 279-2010
Fax(712) 279-2034
Sole ProprietorYes
Medical School CMSUniversity Of Nebraska College Of MedicineGraduated 1991
Enumeration DateSeptember 21, 2005
Last NPPES UpdateJanuary 28, 20264 updates tracked since enumeration
NPPES CertifiedJanuary 28, 2026
✔ NPI 1548256977 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207R00000X
Licenses✔ Licensed in IA · MD-46368✔ Licensed in MT · 91977
Definition
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Also ListedSpecialistTaxonomy 174400000X · License 24459 (AZ)
801 5TH ST, Sioux City, IA 51101
Open in Google Maps ↗

Secondary Practice Locations 3

Location 11821 N Trekell Rd, Suite 6Casa Grande, AZ 85222-1705 · Phone (520) 421-1122 · Fax (520) 421-0751
Location 21 Medical Center DrBiddeford, ME 04005-9422 · Phone (207) 283-7937
Location 31101 26th St SGreat Falls, MT 59405-5161 · Phone (406) 455-4694 · Fax (406) 731-8318

Other Identifiers 3

Medicaid436693002AZ
OtherAZ0866740AZ · Blue Cross Bluee Shield
Other110208816AZ · Medicare Railroad

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Blue Cross Blue Shield of Arizona, Medica.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Frederick Richard Stack Md is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID9638149230
PECOS Enrollment IDI20040730000095, I20210122002608, I20230810000561
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Areas of Expertise CMS Part B claims 5

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
420 services161 patients
Hospital discharge day management, more than 30 minutes 99239
Hospital discharge day management over 30 minutes involves a detailed process to ensure a smooth transition from hospital to home. It includes final examinations, discussion of your hospital stay, post-discharge instructions, and coordinating follow-up care.
122 services121 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
44 services43 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
41 services41 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
23 services14 patients

Hospital Affiliations CMS Care Compare 4

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Cary Medical Center

Acute Care Hospitals · Caribou, ME
3/5 CMS rating
OwnershipGovernment - Local
CMS Certification Number200031
Location163 Van Buren Rd, Suite 1Caribou, ME 04736 · Aroostook County
Emergency services Birthing friendly

Benefis Hospitals Inc

Acute Care Hospitals · Great Falls, MT
2/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number270012
Location1101 26th St SGreat Falls, MT 59405 · Cascade County
Emergency services Birthing friendly

Logan Health - Shelby

Critical Access Hospitals · Shelby, MT
OwnershipVoluntary non-profit - Private
CMS Certification Number271328
Location640 Park AveShelby, MT 59474 · Toole County
Emergency services

Northern Rockies Medical Center

Critical Access Hospitals · Cut Bank, MT
OwnershipVoluntary non-profit - Private
CMS Certification Number271337
Location802 2nd St SECut Bank, MT 59427 · Glacier County

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 51101 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$122.23 typical visit price
range $52.96 – $161.40
Typical copayment $30.55 (range $13.24 – $40.35)
Most-billed visit code 99204
Established Patient
$94.05 typical visit price
range $16.91 – $131.98
Typical copayment $23.51 (range $4.22 – $32.99)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Referred Medical Equipment & Supplies CMS DME claims 3

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Portable gaseous oxygen system, rental; includes portable container, regulator, flowmeter, humidifier, cannula or mask, and tubing E0431
DME-Oxygen and Supplies · category DC000N
5 suppliers23 claims23 services$18.31 avg. paid by Medicare
Oxygen concentrator, single delivery port, capable of delivering 85 percent or greater oxygen concentration at the prescribed flow rate E1390
DME-Oxygen and Supplies · category DC002N
6 suppliers28 claims28 services$100.94 avg. paid by Medicare
Supply allowance for therapeutic continuous glucose monitor (cgm), includes all supplies and accessories, 1 month supply = 1 unit of service K0553
DME-Other DME · category DE017N
1 supplier12 claims12 services$169.80 avg. paid by Medicare
Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MS. KRISTI JO HANSEN P.A.
Physician Assistant
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 279-2512
KIRSTEN MARIE NEDVED
Nurse Practitioner
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 294-7020
NICOLE MARIE KASSING
Physical Therapy Assistant
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 233-5129
MARK EDWARD DAVIS CNP
Nurse Practitioner
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 279-2010
DR. BRETT C. BIEBER PHARM.D. (RPH)
Pharmacist
801 5TH ST, MERCY MEDICAL CENTER - MAIN PHARMACY
SIOUX CITY, IA 51101
Woodbury County (712) 279-5992
GINGER DAWN HAMILTON FNP
Nurse Practitioner
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 279-2010
DEBORAH CARTER CRNA
Nurse Anesthetist, Certified Registered
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 279-2505
DR. PETER JON ANDERSON M.D.
Internal Medicine
801 5TH ST
SIOUX CITY, IA 51101
Woodbury County (712) 279-2010

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Frederick Stack's NPI number?

The NPI number for Frederick Stack is 1548256977. It was assigned to this individual provider in the NPPES registry on September 21, 2005.

Where is Frederick Stack located?

Frederick Stack practices at 801 5th St, Sioux City, IA 51101. The listed phone number is (712) 279-2010.

What is Frederick Stack's specialty?

The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.

Is Frederick Stack enrolled in Medicare?

Yes. Frederick Stack is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

What insurance does Frederick Stack accept?

Health plans from Anthem Blue Cross and Blue Shield, Blue Cross Blue Shield of Arizona and Medica list Frederick Stack as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Frederick Stack affiliated with any hospitals?

According to CMS data, Frederick Stack is affiliated with Cary Medical Center, Benefis Hospitals Inc, Logan Health - Shelby and Northern Rockies Medical Center.

When was this NPI record last updated?

The NPPES record for Frederick Stack was last updated on January 28, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 7 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.