Dr. John E. Fassler, MD
- Medicare services, 2024
- 1,970
- Medicare patients, 2024
- 627
- Part D claims, 2024
- 532
- Hospital affiliations
- 2
- Industry payments
- $1,021
- Practice address
- 1436 Riverchase Blvd, Rock Hill, SC 29732
- Practice phone
- Call (803) 329-2636
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Nephrology Associates PA
Rock Hill, South Carolina
Find Dr. Fassler's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. John E. Fassler is a nephrologist in Rock Hill, South Carolina
Dr. Fassler practices at Nephrology Associates PA in Rock Hill, South Carolina.
Dr. Fassler's NPI, 1891798757, was assigned on May 24, 2005. Dr. Fassler graduated from Ohio State University College of Medicine in 1991. Dr. Fassler holds South Carolina license 19767.
- NPI
- 1891798757NPI Registry (opens in a new tab)
- Medicare PAC ID
- 3870693930
- NPI enumeration date
- May 24, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (803) 329-2636
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 61
- Medical school graduation
- 1991
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John E. Fassler practices at Nephrology Associates PA in Rock Hill, South Carolina
Dr. Fassler's primary practice is Nephrology Associates PA, at 1436 Riverchase Blvd, Rock Hill, SC 29732 in York County. The practice phone is (803) 329-2636.
- Nephrology Associates PA1436 Riverchase Blvd, Rock Hill, SC 29732 · York CountyPhone(803) 329-2636
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. John E. Fassler is affiliated with 6 sites of care and 2 medical groups
Dr. Fassler's primary practice is Nephrology Associates PA in Rock Hill, South Carolina. Dr. Fassler is also affiliated with Rock Hill Hospital - Piedmont Medical Network. The medical group on file is Nephrology Associates. Dmand AI also links Dr. Fassler to 1 more hospital, 2 dialysis centers, 1 group practice or clinic and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; and Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. John E. Fassler's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Fassler practices, 5 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Nephrology Associates PA | Available with a free account |
| +5 more sites and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
For health IT teams
Dmand AI maps EHR vendors, IT decision makers and buying committees across each health system and 6.2K+ hospitals, with verified contacts in the same login.
Dr. John E. Fassler is one of 156 nephrologists in South Carolina
Nephrology is Dr. Fassler's primary specialty in the NPI Registry, under taxonomy code 207RN0300X. Dr. Fassler is licensed in South Carolina.
Specialties and state licenses
- Nephrology, South CarolinaPrimary
Nephrologists near Dr. Fassler
Counts of nephrologists 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. John E. Fassler billed Medicare for 1,970 services in 2024
CMS data shows 1,970 Medicare services from Dr. Fassler across 14 procedure codes in 2024, for 627 Medicare patients. Medicare paid $144,128 for them.
Dr. Fassler's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 1,3002024: 1,03021%
- Other services
- 2023: 02024: 650
- Tests and treatments
- 2023: 4262024: 23545%
- Lab and pathology
- 2023: 762024: 5528%
- Drugs given in the office
- 2023: 1,7102024: 0100%
Where Dr. Fassler's Medicare services took place, 2024
- In an office1,75289%
- In a facility21811%
Dr. Fassler compared with the South Carolina median for nephrologists, 2024
- Dr. Fassler
- South Carolina median
- Medicare services
- 1,970vs 1,63920% above
- Medicare patients
- 627vs 41352% above
- Part D claims
- 343vs 72052% below
Medians across 155 nephrologists in South Carolina with Dmand AI profiles that report each measure.
Dr. Fassler'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.
Need commercial claims for Dr. Fassler?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Fassler and other nephrologists in South Carolina.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. John E. Fassler treated 627 Medicare patients in 2024, average age 75
CMS counts 627 Medicare patients who saw Dr. Fassler in 2024. The largest group is 75 to 84, with 269 patients. 75% of them have chronic kidney disease, and 75% have high blood pressure. 11% are also on Medicaid. Their average risk score is 2.51, 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. Fassler's median patient age at 72, with 51% women.
Dr. Fassler's Medicare patients by age, 2024
Dr. Fassler's Medicare patients by sex, 2024
- Women29647%
- Men33153%
Chronic conditions among Dr. Fassler's Medicare patients, 2024
- Chronic kidney disease75%
- High blood pressure75%
- High cholesterol75%
- Diabetes60%
- Ischemic heart disease45%
- Arthritis44%
- Heart failure36%
- Atrial fibrillation29%
Share of Medicare patients with each condition. A patient can have several.
Dr. Fassler's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 72
Patient panel by sex, all payers
- Women51%
- Men48%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. John E. Fassler wrote 532 Medicare Part D claims in 2024
In 2024, Dr. Fassler wrote 532 Medicare Part D claims for 134 patients. 91% of them were for generic drugs. CMS names the drug for 343 of them, across 13 drugs with 11 or more claims each, at $17,760 in total drug cost. In 2023, CMS named 456 claims across 15 drugs.
Dr. Fassler's Part D claims by kind of drug, 2024
- Generic482 claims91%
- Brand-name50 claims9%
Dr. Fassler'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. Fassler's Part D claims, 2024
- Antibiotics2%12 of 532 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: 4562024: 34325%
Drugs named by CMS: 13 in 2024, 15 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
How Dr. John E. Fassler takes part in Medicare
Dr. Fassler accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
For MedTech and pharma teams
Filter 7.4M+ HCPs by Medicare procedures, Part D drugs and Open Payments history, then reach them with verified contacts in one login.
Dr. John E. Fassler received $1,021 in industry payments from 2016 to 2025
CMS Open Payments shows 35 general payments to Dr. Fassler from 15 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 85% of the total. Mallinckrodt LLC paid the most, $267.
General payments to Dr. Fassler by program year, 2016 to 2025
General payments to Dr. Fassler by kind, 2016 to 2025
- Food and beverage$86885%
- Education$15315%
Companies that paid Dr. Fassler the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. John E. Fassler graduated from Ohio State University College of Medicine
Dr. Fassler graduated from Ohio State University College of Medicine in 1991.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. John E. Fassler'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 | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation 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 | Doctors and Clinicians National Downloadable File (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. John E. Fassler
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. John E. Fassler's NPI number?
Dr. John E. Fassler's NPI number is 1891798757. It was assigned on May 24, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. John E. Fassler?
Dr. John E. Fassler is a nephrologist in Rock Hill, South Carolina. The primary specialty in the NPI Registry is Nephrology Physician (taxonomy code 207RN0300X).
Where does Dr. John E. Fassler practice?
Dr. Fassler practices at 1436 Riverchase Blvd, Rock Hill, SC 29732. Dr. Fassler's primary practice is Nephrology Associates PA in Rock Hill, South Carolina. Dmand AI also links Dr. Fassler to 1 hospital, 2 dialysis centers, 1 group practice or clinic and 1 medical group.
What is Dr. John E. Fassler's office phone number?
The practice phone on file for Dr. Fassler is (803) 329-2636.
What is Dr. John E. Fassler's medical license number?
Dr. Fassler holds South Carolina license 19767.
Which hospitals is Dr. John E. Fassler affiliated with?
Dr. Fassler is affiliated with Rock Hill Hospital - Piedmont Medical Network. Dmand AI links Dr. Fassler to 1 more hospital.
What medical group is Dr. John E. Fassler part of?
Dr. Fassler is linked to Nephrology Associates. Dmand AI links Dr. Fassler to 1 more medical group.
Does Dr. John E. Fassler accept Medicare?
Yes. CMS data shows Dr. Fassler billed Medicare for 1,970 services in 2024, and Dr. Fassler accepts Medicare assignment.
How many Medicare patients does Dr. John E. Fassler see?
CMS counts 627 Medicare patients who saw Dr. Fassler in 2024, with an average age of 75.
What services does Dr. John E. Fassler bill to Medicare?
In 2024, Dr. Fassler's most billed Medicare services were medicare service (G2211), office visit, established patient (99214) and dialysis (90960).
Show 4 more questionsShow fewer questions
Where did Dr. John E. Fassler go to medical school?
Dr. Fassler graduated from Ohio State University College of Medicine in 1991.
What drugs does Dr. John E. Fassler prescribe most?
In 2024 Medicare Part D data, Dr. Fassler's most prescribed drugs by claims were Amlodipine Besylate, Metoprolol Succinate and Furosemide.
Has Dr. John E. Fassler received payments from drug or device companies?
CMS Open Payments shows $1,021 in general payments to Dr. Fassler from 15 companies from 2016 to 2025. The largest total came from Mallinckrodt LLC.
How long has Dr. John E. Fassler been practicing?
Dr. Fassler graduated from medical school in 1991, 35 years ago.
Selling to nephrology practices?
See nephrologists in South Carolina by site of care and group
Find the practices, groups and hospitals they work with, and the right people to contact at each.
- 30 days free
- Self-serve
- No credit card