Dr. Alexander Nathaniel Fleischhacker , DO
Internal Medicine โข Gainesville, FL
1600 Sw Archer Rd
Gainesville, FL 326103003
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
-
Dr. Alexander Fleischhacker is listed in NPPES under Internal Medicine.
-
NPI assigned on May 23, 2021; this date does not establish years in practice.
-
Published CMS data list 106 Original Medicare Part B services in 2024.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Published rows only; this is not a quality measure.
-
Published Part B service records, 2024:
- 99223 โ Initial hospital care with moderate level of medical decision making: 106 service units.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Units differ by code; these are not visits or a measure of quality.
CPTยฎ only copyright 2023 American Medical Association. All rights reserved. Service names are shortened from CPT Consumer Friendly Descriptors (CMS data, 2024). CPT notice
See the full table ยท Guide: How to read Medicare Part B data
-
Published CMS data list 28 Medicare Part D prescriptions, including refills, in 2024.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2024. Published rows only; this is not a quality measure.
-
Published Part D records, 2024:
- Atorvastatin Calcium โ 14 prescription fills, including refills.
- Nifedipine Er (Nifedipine) โ 14 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2024. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See the full table ยท Guide: How to read Medicare Part D prescriber data
-
Fewer Medicare Part B services than 90% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 166 clinicians with data). Median for this group: 722. Middle half: 383 to 1,286.
Fewer Medicare Part B services than 85% of clinicians listed under Internal Medicine in Florida (2024, 5,815 clinicians with data). Median for this group: 687. Middle half: 277 to 1,489.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Billing and prescribing volume is not a quality rating.
-
Medicare Part D prescriptions went from 38 in 2023 to 28 in 2024.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2023โ2024.
Practice Location & Contact Primary Location
1600 Sw Archer Rd
Gainesville, FL 326103003
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Internal Medicine: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare patients
115 people with Original Medicare in 2024
It gives a sense of how many people with Medicare this clinician treated that year.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider, 2024.
Medicare-allowed amount
About $17,982 in 2024
The total amount Medicare approved for these services in 2024. It includes what Medicare paid and what patients or their other insurance owed, such as the deductible and coinsurance.
It shows the total cost of this clinician's Original Medicare services under Medicare's fee rules.
What this does not show: Medicare-allowed amount
This is not the clinician's income. Part of it can go to a clinic or group practice, staff, equipment or drugs. It is not the price you will pay.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
Paid by Medicare
About $14,231 in 2024
The part of the Medicare-allowed amount that Medicare itself paid in 2024, after patients' deductibles and coinsurance.
The gap between the allowed amount and this number is roughly what patients and their other insurance paid.
What this does not show: Paid by Medicare
This is not the clinician's income and not a measure of quality.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
30-day fills
54 standardized 30-day fills in 2024
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$278 in 2024
The total cost of these prescriptions in 2024, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2024.
Industry payments (Open Payments)
Fewer than 11 payment records totaling $123.06 in 2025
Drug and medical device companies must report certain payments to doctors and some other clinicians to CMS, such as meals, travel, speaking fees or research funding.
It shows reported financial ties between this clinician and companies. You can ask your clinician about them.
These records are submitted by drug and medical device companies, and a reported payment does not necessarily mean the financial relationship is improper.
General: payments not tied to research, such as meals, travel, consulting or speaking fees.
A reported payment does not necessarily mean the financial relationship is improper. Research payments can go to a hospital or university for a study the clinician leads, not to the clinician personally. Clinicians can dispute records with the company that reported them.
Source: CMS Open Payments, program year 2025.
NPI first issued
2021
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, โDoes your provider accept Medicare as full payment?โ
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Enrolled in Medicare (PECOS)
Dr. Fleischhacker has a Medicare enrollment record in PECOS, the CMS system clinicians use to enroll so they can bill Medicare or order services for people with Medicare.
It does not show whether the clinician accepts assignment, is in your plan's network, or is taking new patients.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Can order Medicare-covered services
CMS lists Dr. Fleischhacker as eligible to order or refer Medicare Part B clinical laboratory and imaging services, durable medical equipment (DME) and home health services for people with Medicare.
Medicare pays for these items and services only when they are ordered by an eligible clinician.
What this does not show: Can order Medicare-covered services
It does not mean the clinician offers these services directly.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Compared with the same specialty in Gainesville and Florida
Billing and prescribing volume is not a quality rating.
Medicare Part B services
Fewer Medicare Part B services than 90% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 166 clinicians with data). Median for this group: 722. Middle half: 383 to 1,286.
Fewer Medicare Part B services than 85% of clinicians listed under Internal Medicine in Florida (2024, 5,815 clinicians with data). Median for this group: 687. Middle half: 277 to 1,489.
Medicare-allowed amount
A lower Medicare-allowed amount than 85% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 166 clinicians with data). Median for this group: $75,713. Middle half: $42,942 to $110,012.
A lower Medicare-allowed amount than 80% of clinicians listed under Internal Medicine in Florida (2024, 5,815 clinicians with data). Median for this group: $68,256. Middle half: $27,620 to $138,398.
Paid by Medicare
A lower Medicare payment amount than 85% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 166 clinicians with data). Median for this group: $59,923. Middle half: $31,198 to $82,955.
A lower Medicare payment amount than 80% of clinicians listed under Internal Medicine in Florida (2024, 5,815 clinicians with data). Median for this group: $52,728. Middle half: $20,807 to $107,475.
Medicare Part D prescriptions
Fewer Part D prescriptions than 85% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 149 clinicians with data). Median for this group: 369. Middle half: 69 to 2,736.
Fewer Part D prescriptions than 90% of clinicians listed under Internal Medicine in Florida (2024, 6,545 clinicians with data). Median for this group: 1,318. Middle half: 158 to 5,882.
Part D drug cost
A lower Part D drug cost than 85% of clinicians listed under Internal Medicine in Gainesville, FL (2024, 149 clinicians with data). Median for this group: $21,368. Middle half: $2,230 to $200,110.
A lower Part D drug cost than 90% of clinicians listed under Internal Medicine in Florida (2024, 6,545 clinicians with data). Median for this group: $86,865. Middle half: $8,159 to $434,445.
290 active clinicians are listed under Internal Medicine with a practice address in Gainesville, FL (10,165 in Florida).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Gainesville
13.1% of these 290 clinicians have the CMS telehealth indicator.
49.3% of these 290 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
-
Medicare Part B services
CMS data for Medicare Part B services are available for 2024 only.
-
Medicare-allowed amount
CMS data for Medicare-allowed amount are available for 2024 only.
-
Paid by Medicare
CMS data for Medicare payment amount are available for 2024 only.
-
Medicare Part D prescriptions
Medicare Part D prescriptions decreased 26% from 38 in 2023 to 28 in 2024.
- 2023: 38
- 2024: 28
-
30-day fills
30-day fills decreased 43% from 94 in 2023 to 54 in 2024.
- 2023: 94
- 2024: 54
-
Part D drug cost
Part D drug cost went from $328 in 2023 to $278 in 2024.
- 2023: $328
- 2024: $278
-
Industry payments (Open Payments)
Industry payments (Open Payments) went from $45.93 in 2024 to $123.06 in 2025.
- 2024: $45.93
- 2025: $123.06
Sources: CMS Medicare Physician & Other Practitioners (2024), CMS Medicare Part D Prescribers (2024), CMS Open Payments (2025), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo ยท Report an error.
Pharma & Medical Device Financial Disclosures
Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments
Program year 2025 (payments made January 1 โ December 31, 2025): fewer than 11 records totaling $123.06.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Bristol Myers Squibb Company |
Food and Beverage
Cash or cash equivalent
|
COBENFY | General | $123.06 |
Source: CMS Open Payments, program year 2025, released June 30, 2026.
Performed Procedures & Service Volume
CPTยฎ is a registered trademark of the American Medical Association. CPT codes, descriptions and other data only are copyright 2023 American Medical Association. All rights reserved. Applicable FARS/HHSARS apply. Descriptions of CPT codes are the AMA's CPT Consumer Friendly Descriptors as published by CMS in the Medicare Physician & Other Practitioners โ by Provider and Service data, 2024; they are plain-language summaries, not for clinical coding or documentation. HCPCS Level II codes and descriptions are from CMS. Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.
| HCPCS Code | Services | Patients | Submitted Charge | Medicare Allowed |
|---|---|---|---|---|
|
99223
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes
|
106 | 104 | $648.00 | $169.64 |
Source: CMS Part B by Provider and Service, 2024; services under 11 beneficiaries omitted by CMS. Privacy limits
Submitted charges are billed amounts, not a price quote for your visit.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2024.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Atorvastatin Calcium | Atorvastatin Calcium | 14 | 1,140 | $140.67 | โ |
| Nifedipine Er | Nifedipine | 14 | 480 | $136.99 | โ |
Source: CMS Part D by Provider and Drug, 2024; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
Self-certified to NPPES: 2024-09-11NUCC Taxonomy Code: 207R00000X
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.
NUCC Taxonomy Code: 390200000X
An individual who is enrolled in an organized health care education/training program leading to a degree, certification, registration, and/or licensure to provide health care.
Medicare (PECOS) Enrollment & Ordering Eligibility
Source: CMS PECOSPRACTITIONER - HOSPITALIST
I20240801002124
FL
2769884188
Sources: CMS Provider Enrollment and Order and Referring. Medicare enrollment is a billing status, not an accreditation or quality rating.
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Radiology - Diagnostic Radiology
Doctor of Medicine (M.D.)
Internal Medicine - Gastroenterology
Internal Medicine - Cardiovascular Disease
Doctor of Medicine (M.D.)
Family Medicine
Doctor of Medicine (M.D.)
Emergency Medicine
Doctor of Osteopathic Medicine (D.O.)
Internal Medicine - Infectious Disease
Doctor of Medicine (M.D.)
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at PO BOX 100238, GAINESVILLE, FL 326100238 (Tel: 3522948278)
Student in an Organized Health Care Education/Training Program
Registered at 1600 SW ARCHER RD, GAINESVILLE, FL 326103003 (Tel: 3522650379)
Internal Medicine (license number reported to NPPES: FL 21045)
NPI status registered as active in NPPES database
Registered at 4725 N FEDERAL HWY, FORT LAUDERDALE, FL 333084603 (Tel: 8584429627)
Registered at 4725 N FEDERAL HWY, FORT LAUDERDALE, FL 333084603 (Tel: 8584429627)
Recorded as ALEXANDER FLEISCHHACKER, DO
Student in an Organized Health Care Education/Training Program
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Internal Medicine Providers in Gainesville
- Dr. Mary Waechter, MD
- Dr. Muhammad Ali, MD
- Dr. Kanika Rathi, MD
- Dr. Syed Shah, MD
- Dr. Anugya Poudel-Chataut, MD
- Dr. Allen Brasington, MD
Mailing Address
Po Box 100238
Gainesville, FL 326100238
Phone: 3522948278