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Dermatology

Margaret A. Fonder, MD

Sees patients in Ridgewood, NJ · New Jersey

Summary

Dr. Margaret A. Fonder, MD is a dermatologist at 400 Route 17, Ridgewood, NJ 07450. Phone: (201) 652-4536. Accepts Medicare assignment. In 2024, Margaret A. Fonder had 443 Original Medicare patients and 4,171 services. NPI 1962689133. Source: CMS National Downloadable File, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

  • Specialty: Dermatologist (Medicare lists Dermatology)
  • Address: 400 Route 17, Ridgewood, NJ 07450 · Directions
  • Phone: (201) 652‑4536
  • Medicare: Accepts Medicare assignment
  • Group practice: Bergen Dermatology Specialists PA
  • Medical school: Johns Hopkins University School Of Medicine · graduated 2007 (19 years since medical school)
  • Gender (as listed): Female

From official Medicare data

This page shows what Medicare's official clinician data says about Margaret A. Fonder, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Margaret A. Fonder accept Medicare assignment?
Yes. Medicare's clinician data says Margaret A. Fonder accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
How many Medicare patients does Margaret A. Fonder see?
In 2024, CMS data shows 443 Original Medicare patients and 4,171 services for Margaret A. Fonder. This counts Original Medicare only and measures volume, not quality.
What is Margaret A. Fonder's NPI number?
1962689133. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Medicare activity in 2024

Official CMS public-use data for Margaret A. Fonder, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Original Medicare patients443
Services billed to Medicare4,171
Different services or procedures49
Participating Medicare providerYes
Average age of these patients76

Most frequent services

  1. Destruction of precancer skin growth, 2-14 growths (17003)889 services
  2. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)499 services
  3. Destruction of precancer skin growth, 1 growth (17000)287 services
  4. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)216 services
  5. Biopsy of related skin growth, first growth (11102)181 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

  • High cholesterol75%
  • High blood pressure70%
  • Arthritis47%
  • Ischemic heart disease29%
  • Osteoporosis24%
  • Cancer (breast, colorectal, lung, prostate, endometrial or leukemia/lymphoma)23%

Practice locations

Addresses where Margaret A. Fonder is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Margaret A. Fonder as a member of this group (CMS data updated October 2, 2026).

  • Bergen Dermatology Specialists PA6 clinicians in the group

Specialties

Find other Dermatology doctors in New Jersey →

Other dermatologists in New Jersey

Clinicians with the same Medicare primary specialty in New Jersey — not a recommendation.

All dermatologists in New Jersey →

Other clinicians in Bergen Dermatology Specialists PA

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Medical schoolJohns Hopkins University School Of Medicine
Graduation year2007 (19 years since medical school)
Gender (as listed)Female
Medicare assignmentAccepts (Medicare-approved amount as full payment)
NPI (National Provider Identifier)1962689133
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  2. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  3. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  4. Medicare Care Compare — official Medicare tool to look up clinicians