Dr. Alexander Nathaniel Fleischhacker, DO
- Medicare services, 2024
- 106
- Medicare patients, 2024
- 115
- Part D claims, 2024
- 170
- MIPS score, 2024
- 48
- Hospital affiliations
- 1
- Practice address
- 451 Clarkson Avenue, Brooklyn, NY 11203
- Practice phone
- Call (718) 245-3901
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Fleischhacker's professional email, personal email and mobile number
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Dr. Alexander Nathaniel Fleischhacker is an internist in Brooklyn, New York
Dr. Fleischhacker practices at NYC Health + Hospitals/Kings County in Brooklyn, New York, part of NYC.
Dr. Fleischhacker's NPI, 1578138533, was assigned on May 23, 2021. Dr. Fleischhacker graduated from Dr. Kiran C. Patel College of Osteopathic Medicine in 2021. Dr. Fleischhacker holds Florida license OS21045.
- NPI
- 1578138533NPI Registry (opens in a new tab)
- NPI enumeration date
- May 23, 2021
- NPI status
- Active
- Practice phone
- (718) 245-3901
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 31
- Medical school graduation
- 2021
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Affiliation Data
Dr. Alexander Nathaniel Fleischhacker practices at NYC Health + Hospitals/Kings County in Brooklyn, New York
Dr. Fleischhacker's primary practice is NYC Health + Hospitals/Kings County, at 451 Clarkson Avenue, Brooklyn, NY 11203 in Kings County. The practice phone is (718) 245-3901.
- NYC Health + Hospitals/Kings County451 Clarkson Avenue, Brooklyn, NY 11203 · Kings CountyPhone(718) 245-3901
Source: Dmand AI Affiliation Data
Dr. Alexander Nathaniel Fleischhacker is affiliated with 1 site of care and 1 medical group
Dr. Fleischhacker's primary practice is NYC Health + Hospitals/Kings County in Brooklyn, New York, part of NYC. The medical group on file is UF Health Physicians.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Alexander Nathaniel Fleischhacker's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Fleischhacker practices. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| NYC Health + Hospitals/Kings County | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Alexander Nathaniel Fleischhacker is one of 9,643 internists in New York
Internal medicine is Dr. Fleischhacker's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Fleischhacker is board certified in internal medicine by the American Board of Internal Medicine. Dr. Fleischhacker is licensed in Florida.
Specialties and state licenses
- Internal medicine, FloridaPrimary
Internists near Dr. Fleischhacker
Counts of internists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Alexander Nathaniel Fleischhacker billed Medicare for 106 services in 2024
CMS data shows 106 Medicare services from Dr. Fleischhacker across 1 procedure code in 2024, for 115 Medicare patients. Medicare paid $14,230 for them. Every service was in a facility, such as a hospital, rather than an office.
Dr. Fleischhacker compared with the New York median for internists, 2024
- Dr. Fleischhacker
- New York median
- Medicare services
- 106vs 42675% below
- Medicare patients
- 115vs 15827% below
- Part D claims
- 28vs 62295% below
Medians across 9,428 internists in New York with Dmand AI profiles that report each measure.
Dr. Fleischhacker's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Fleischhacker and other internists in New York.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Alexander Nathaniel Fleischhacker treated 115 Medicare patients in 2024, average age 76
CMS counts 115 Medicare patients who saw Dr. Fleischhacker in 2024. The largest group is 75 to 84, with 44 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 29% are also on Medicaid. Their average risk score is 2.71, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Fleischhacker's median patient age at 74, with 50% women.
Dr. Fleischhacker's Medicare patients by age, 2024
Dr. Fleischhacker's Medicare patients by sex, 2024
- Women5245%
- Men6355%
Chronic conditions among Dr. Fleischhacker's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Ischemic heart disease65%
- Arthritis62%
- Heart failure56%
- Chronic kidney disease54%
- Diabetes54%
- Depression50%
Share of Medicare patients with each condition. A patient can have several.
Dr. Fleischhacker's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 74
Patient panel by sex, all payers
- Women50%
- Men50%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Alexander Nathaniel Fleischhacker wrote 170 Medicare Part D claims in 2024
In 2024, Dr. Fleischhacker wrote 170 Medicare Part D claims for 53 patients. 92% of them were for generic drugs. CMS names the drug for 28 of them, across 2 drugs with 11 or more claims each, at $278 in total drug cost. In 2023, CMS named 38 claims across 2 drugs.
Dr. Fleischhacker's Part D claims by kind of drug, 2024
- Generic156 claims92%
- Brand-name14 claims8%
Dr. Fleischhacker's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Fleischhacker's Part D claims, 2024
- Antibiotics8%13 of 170 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 382024: 2826%
Drugs named by CMS: 2 in 2024, 2 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
Dr. Alexander Nathaniel Fleischhacker scored 48 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 48 out of 100 for Dr. Fleischhacker for performance year 2024, reported through an alternative payment model (APM).
Dr. Fleischhacker's MIPS scores, performance year 2024
- 48of 100Final score
- 38.5of 100Quality
- 0of 100Promoting Interoperability
- 40of 100Improvement Activities
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Source: Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Dr. Alexander Nathaniel Fleischhacker received $169 in industry payments from 2024 to 2025
CMS Open Payments shows 3 general payments to Dr. Fleischhacker from 3 drug and device companies from 2024 to 2025. Food and beverage make up the largest share, 100% of the total. Bristol-Myers Squibb Company paid the most, $123.
General payments to Dr. Fleischhacker by program year, 2024 to 2025
Companies that paid Dr. Fleischhacker the most, 2024 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Alexander Nathaniel Fleischhacker graduated from Dr. Kiran C. Patel College of Osteopathic Medicine
Dr. Fleischhacker graduated from Dr. Kiran C. Patel College of Osteopathic Medicine in 2021.
- Medical school
- Board certified in internal medicine
- Board certified in 2024 - 2026
- Board certified in 2025 - 2027
Source: Dmand AI Professional Profile Data
Sources for Dr. Alexander Nathaniel Fleischhacker's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Alexander Nathaniel Fleischhacker
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Alexander Nathaniel Fleischhacker's NPI number?
Dr. Alexander Nathaniel Fleischhacker's NPI number is 1578138533. It was assigned on May 23, 2021, and it is active in the NPI Registry.
What kind of doctor is Dr. Alexander Nathaniel Fleischhacker?
Dr. Alexander Nathaniel Fleischhacker is an internist in Brooklyn, New York. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Alexander Nathaniel Fleischhacker practice?
Dr. Fleischhacker practices at 451 Clarkson Avenue, Brooklyn, NY 11203. Dr. Fleischhacker's primary practice is NYC Health + Hospitals/Kings County in Brooklyn, New York, part of NYC.
What is Dr. Alexander Nathaniel Fleischhacker's office phone number?
The practice phone on file for Dr. Fleischhacker is (718) 245-3901.
What is Dr. Alexander Nathaniel Fleischhacker's medical license number?
Dr. Fleischhacker holds Florida license OS21045.
Which hospitals is Dr. Alexander Nathaniel Fleischhacker affiliated with?
Dr. Fleischhacker practices at NYC Health + Hospitals/Kings County in Brooklyn, New York.
What medical group is Dr. Alexander Nathaniel Fleischhacker part of?
Dr. Fleischhacker is linked to UF Health Physicians.
Does Dr. Alexander Nathaniel Fleischhacker accept Medicare?
Yes. CMS data shows Dr. Fleischhacker billed Medicare for 106 services in 2024.
What is Dr. Alexander Nathaniel Fleischhacker's MIPS score?
Dr. Fleischhacker's MIPS final score for performance year 2024 is 48 out of 100, reported through an alternative payment model (APM).
How many Medicare patients does Dr. Alexander Nathaniel Fleischhacker see?
CMS counts 115 Medicare patients who saw Dr. Fleischhacker in 2024, with an average age of 76.
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Is Dr. Alexander Nathaniel Fleischhacker board certified?
Yes. Dr. Fleischhacker is board certified in internal medicine by the American Board of Internal Medicine.
What services does Dr. Alexander Nathaniel Fleischhacker bill to Medicare?
In 2024, Dr. Fleischhacker's most billed Medicare services were hospital inpatient care (99223).
Where did Dr. Alexander Nathaniel Fleischhacker go to medical school?
Dr. Fleischhacker graduated from Dr. Kiran C. Patel College of Osteopathic Medicine in 2021.
What drugs does Dr. Alexander Nathaniel Fleischhacker prescribe most?
In 2024 Medicare Part D data, Dr. Fleischhacker's most prescribed drugs by claims were Atorvastatin Calcium and Nifedipine ER.
Has Dr. Alexander Nathaniel Fleischhacker received payments from drug or device companies?
CMS Open Payments shows $169 in general payments to Dr. Fleischhacker from 3 companies from 2024 to 2025. The largest total came from Bristol-Myers Squibb Company.
How long has Dr. Alexander Nathaniel Fleischhacker been practicing?
Dr. Fleischhacker graduated from medical school in 2021, 5 years ago.
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