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Edit this profileAt a glance
- 101 S Ellsworth Ave, Suite 607, San Mateo, CA 94401
About Dr. Diefendorf
Based in San Mateo, CA, Dirk R. Diefendorf, M.D. is listed in the NPI registry under orthopedic surgery. Dirk graduated from Northwestern University Feinberg Medical School in 1983. Medicare claims data shows Dirk provided 474 services to 328 patients. The services billed most often include established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more, established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, and new patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more. NPI 1467559443 identifies this record in the national registry.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (650) 347-0157
- Email not available
Is this your home address or personal number? Hide it
Practice Locations
101 S ELLSWORTH AVE SUITE 607
San Mateo, CA 94401
Conditions Commonly Evaluated or Treated
Within Orthopedic Surgery generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Pain
Pediatric and tumor
- Slipped capital femoral epiphysis
Spine
- Cervical spondylosis
- Lumbar spondylosis
- Herniated disc
- Scoliosis
- Spinal stenosis
Most searched conditions
Elbow, hand, and wrist
- Cubital tunnel syndrome
- Golfer's elbow
- Tennis elbow
- Trigger finger
- Wrist fracture
Foot and ankle
Hip
Shoulder
- Broken collarbone
- Frozen shoulder
- Shoulder impingement
- Dislocated joint
Sports and soft tissue
Trauma and bone
Foot & Ankle
Procedures & services
Ankle surgery
Evaluation and nonsurgical
- Closed fracture treatment
- Joint injection or aspiration
- Orthopedic evaluation
- Cast placement and management
Foot & Ankle
- Ankle Ligament Surgery
- Hammertoe Surgery
Foot and ankle
- Ankle arthroscopy
- Ankle fusion
- Total ankle replacement
- Bunion surgery
Hand and upper extremity
- Wrist fracture fixation
- Cubital tunnel decompression
- Dupuytren contracture surgery
- Trigger finger release
Joint replacement
- Total hip replacement
- Total knee replacement
- Partial knee replacement
- Reverse shoulder replacement
- Revision joint replacement
- Shoulder replacement
Nerves & spine
- Spine surgery consultation
Orthopedics
- ACL reconstruction consultation
- Carpal tunnel surgery consultation
- Hip replacement consultation
- Knee replacement consultation
- Torn rotator cuff consultation
Post-Op Care
- Cast Removal
Spine
- Anterior cervical discectomy and fusion
Spine & Orthopedics
- Bunion Surgery Consultation
- Foot and Ankle Surgery Consultation
- Shoulder Surgery Consultation
- Surgical Hardware Removal Consultation
- Trigger Finger Release Consultation
Trauma and fixation
- External fracture fixation
- Intramedullary nailing
- Repair of fracture nonunion
- Open reduction and internal fixation
Tumor and pediatric
- Bone or soft-tissue tumor resection
- Limb-sparing cancer surgery
- Pediatric corrective osteotomy
Most searched procedures
- Achilles tendon repair
- ACL reconstruction
- Carpal tunnel surgery
- Hip replacement
- Knee replacement
Arthroscopy
- Hip arthroscopy
- Rotator cuff repair
- Shoulder arthroscopy
Hand & Wrist
- De Quervain's Release
Injections & Non-Surgical
Injections & pain relief
- Cortisone Shot for Joint Pain
Knee
- Kneecap Stabilization Surgery
- Meniscus Surgery
Shoulder surgery
- Shoulder labrum repair
Trauma & Fractures
- Broken Hip Surgery
- Hardware Removal Surgery
Procedures Most Often Billed to Medicare
474 services · 328 patients · 5 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
274 | More often than most peers in Orthopedic Surgery |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
89 | As often as other peers in Orthopedic Surgery |
| New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more | Office visit | 99204 |
83 | Too few peers to compare |
| New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more | Office visit | 99203 |
17 | Less often than most peers in Orthopedic Surgery |
| New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more | Office visit | 99205 |
11 | Too few peers to compare |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Related specialists at this location 2
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Trained at Northwestern University Feinberg Medical School 1
Other providers in the same specialty who trained at the same institution.
More connections — 8 related providers in 1 group
Class of 1983 at Northwestern University Feinberg Medical School 8
Providers who graduated from the same medical school in the same year.
Common questions
What is Dirk R. Diefendorf's specialty?
Dirk R. Diefendorf is an orthopedic surgeon in San Mateo, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Orthopedic Surgery”.
NPI registry
Where can I find Dirk R. Diefendorf?
Dirk R. Diefendorf is listed at 101 S Ellsworth Ave Suite 607, San Mateo, CA 94401. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How do I contact Dirk R. Diefendorf?
The number on file is (650) 347-0157. Contact the office directly to confirm availability and scheduling.
NPI registry
What is the NPI for Dirk R. Diefendorf?
Dirk R. Diefendorf's National Provider Identifier is 1467559443. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
What is Dirk R. Diefendorf's education?
Dirk R. Diefendorf attended Northwestern University Feinberg Medical School, graduating in 1983. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dirk R. Diefendorf have?
Dirk R. Diefendorf has 43 years experience. Calculated from a graduation year of 1983, reported in the CMS National Downloadable File.
CMS public data
What is Dirk R. Diefendorf known for?
According to Medicare billing data, Dirk R. Diefendorf the Medicare record under this individual NPI shows mainly office visits and diagnostic testing. Hospital-based physicians usually have their procedural work billed by the facility rather than under their own number, so this is a floor on their practice, not a description of it. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dirk R. Diefendorf's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dirk R. Diefendorf. If this is you, claiming it is free.
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