DR. JOHN NICHOLAS DIANA M.D.
NPI 1649297540
Orthopaedic Surgery - Adult Reconstructive Orthopaedic Surgery in Napa, CA

Q: What is John Diana's NPI number?

The NPI number for John Diana is 1649297540. It was assigned to this individual provider in the NPPES registry on July 16, 2006.

Q: What is John Diana's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Adult Reconstructive Orthopaedic Surgery, with taxonomy code 207XS0114X.

Q: When was this NPI record last updated?

The NPPES record for John Diana was last updated on October 22, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since July 16, 2006PECOS EnrolledAccepts Medicare Assignment

91.59/100

CMS Quality Rating

3273 CLAREMONT WAY, SUITE 100, NAPA, CA 94558(707) 254-7117(707) 265-6435 Get Directions Write a Review

NPPES record last updated: October 22, 2014. Verified against the NPPES registry weekly; last sync: November 08, 2026.

On this page

About Dr. John Nicholas Diana M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. JOHN NICHOLAS DIANA M.D. (NPI 1649297540) is an individual adult reconstructive orthopaedic surgery provider in Napa, California, licensed in California (A87859) and active in the NPI registry since July 2006. He is enrolled in Medicare PECOS and is a graduate of Indiana University School Of Medicine (1996).

NPPES Registry Identity

NPI1649297540

Entity TypeIndividualMale

Primary Taxonomy207XS0114X

Provider Legal NameDR. JOHN NICHOLAS DIANACredential: M.D.

Location Address3273 CLAREMONT WAY, SUITE 100Napa, CA 94558-3306

Mailing Address3273 Claremont Way, Suite 100Napa, CA 94558-3306 · (707) 254-7117 · Fax (707) 265-6435

Phone(707) 254-7117

Fax(707) 265-6435

Sole ProprietorNo

Medical School CMSIndiana University School Of MedicineGraduated 1996

Enumeration DateJuly 16, 2006

Last NPPES UpdateOctober 22, 2014

✔ NPI 1649297540 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyOrthopaedic Surgery · Adult Reconstructive Orthopaedic SurgeryAllopathic & Osteopathic Physicians

Taxonomy Code207XS0114X

License✔ Licensed in CA · A87859

Definition

Recognized by several state medical boards as a fellowship subspecialty program of orthopaedic surgery, adult reconstructive orthopaedic surgeons deal with reconstructive procedures such as joint arthroplasty (i.e., hip and knee), osteotomy, arthroscopy, soft-tissue reconstruction, and a variety of other adult reconstructive surgical procedures.

Also ListedOrthopaedic Surgery · Sports MedicineTaxonomy 207XX0005X · License A87859 (CA)

Also ListedOrthopaedic Surgery · Orthopaedic TraumaTaxonomy 207XX0801X · License A87859 (CA)

3273 CLAREMONT WAY, Napa, CA 94558

Open in Google Maps ↗

Other Identifiers 4

OtherA87859CA · License

Medicare UPINH32506CA

Medicare PIN00A878590CA

Medicaid00A878590CA

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. John Nicholas Diana M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID2365404373

PECOS Enrollment IDI20041103000333

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignments

Medicare enrollment records show John Diana reassigns Medicare billing to 3 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Adventist Health Physicians Network

Same address

Surgery

3273 CLAREMONT WAY, SUITE 201
Napa, CA 94558

Reassigned Medicare billing, California enrollment
678 clinicians in this Medicare group

NPI 1083025209 (707) 252-0313

Napa Valley Orthopaedic Medical Group, Inc

Same address

Orthopaedic Surgery

3273 CLAREMONT WAY, SUITE 100
Napa, CA 94558

Reassigned Medicare billing, California enrollment
9 clinicians in this Medicare group

NPI 1710934575 (707) 254-7117

St. Helena Hospital

14 mi

Psychiatric Hospital

525 OREGON ST
Vallejo, CA 94590

Reassigned Medicare billing, California enrollment
128 clinicians in this Medicare group

NPI 1851381990 (707) 648-2200

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 24

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3301

Triamcinolone acetonide is a medication used to reduce inflammation in the body. It's given as a 10 mg injection for conditions like allergies, arthritis, or skin problems. The injection helps to decrease swelling, redness, and itching.

344 services72 patients

X-ray of knee, 4 or more views 73564

An X-ray of the knee, 4 or more views, is a non-invasive imaging test. It involves capturing multiple images of your knee from different angles. This helps in diagnosing conditions such as fractures, arthritis, or infections. The procedure is quick and painless.

289 services173 patients

Replacement of knee joint, both sides of knee 27447

A bilateral knee joint replacement is a procedure where the damaged parts of both your knee joints are replaced with artificial parts. It aims to relieve pain and improve mobility. The process involves a surgical operation under anesthesia.

207 services195 patients

X-ray of knee, 3 views 73562

An X-ray of the knee, 3 views, is a non-invasive imaging test. It uses a small amount of radiation to produce images of the knee from three different angles. This helps medical professionals to diagnose and monitor conditions like arthritis, fractures, or infections. The process is quick and painless.

204 services148 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

203 services190 patients

X-ray of hip, 2-3 views 73502

An X-ray of the hip with 2-3 views is a non-invasive imaging test. It uses a small amount of radiation to produce pictures of the hip joint. These images help in diagnosing conditions like fractures, arthritis, or other abnormalities. The process is quick and painless.

146 services109 patients

X-ray of hip, 2-3 views 73502

145 services125 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

135 services121 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

130 services130 patients

Replacement of thigh bone and hip joint with prosthesis 27130

This procedure, known as hip arthroplasty, involves replacing your damaged thigh bone and hip joint with artificial parts, called a prosthesis. It helps relieve pain, improve mobility, and enhance your quality of life.

122 services115 patients

Computer-assisted surgery for muscle and bone procedure 20985

Computer-assisted surgery for muscle and bone procedures involves using a computer to aid in planning and performing surgery. This technology helps increase precision, reduce invasiveness, and improve outcomes. It's commonly used in orthopedic surgeries like joint replacements.

120 services116 patients

Aspiration and/or injection of fluid from large joint 20610

This procedure involves using a needle to remove (aspiration) or introduce (injection) fluid into a large joint like the knee or hip. It can help diagnose conditions, relieve discomfort, or deliver medication directly to the joint.

94 services81 patients

X-ray of knee, 3 views 73562

85 services75 patients

Aspiration and/or injection of fluid from large joint 20610

69 services67 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

69 services67 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

68 services68 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

64 services64 patients

X-ray of knee, 4 or more views 73564

60 services48 patients

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203

This service involves an initial office or outpatient visit for a new patient. The healthcare professional will spend 30-44 minutes understanding your health history, current issues, and discussing possible treatment plans. It's a comprehensive evaluation to start your healthcare journey.

41 services41 patients

Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more 99212

This is a routine check-up for patients who have previously seen the doctor. During this 10-19 minute visit, the doctor will review your health status, discuss any concerns, and manage ongoing treatments or medications. It's a chance to ensure your health is on track.

30 services29 patients

Fluoroscopic guidance for needle placement 77002

Fluoroscopic guidance for needle placement is a medical procedure that uses a special X-ray technology to help accurately place a needle in the body. It's often used in biopsies, injections or other treatments to ensure precision and safety.

29 services25 patients

New patient office or other outpatient visit with low level of medical decision making, if using time, 30 minutes or more 99203

22 services22 patients

X-ray of both hips, 2 views 73521

An X-ray of both hips, 2 views, is an imaging test that uses a small amount of radiation to create detailed pictures of your hip joints. This procedure helps to detect fractures, infections, or other abnormalities in the hip area. Two different angles will be captured for a comprehensive assessment.

15 services15 patients

Manipulation of knee joint under anesthesia 27570

Manipulation of the knee joint under anesthesia is a procedure done to improve knee mobility. You are put to sleep and the doctor moves your knee in different directions to break up scar tissue. This helps to increase range of motion and reduce stiffness.

12 services12 patients

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

91.59/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored through an Alternative Payment Model

Quality

85.05

Promoting Interoperability

96.88

Improvement Activities

Reported Quality Measures

Risk-standardized complication rate (RSCR) following elective primary total hip arthroplasty (THA) and/or total knee arthroplasty (TKA) for Merit-based Incentive Payment System (MIPS)

Lower rates are better for this measure.

0.03%

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES 19

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

ADVENTIST HEALTH PHYSICIANS NETWORK

Surgery

3273 CLAREMONT WAY, SUITE 201
NAPA, CA 94558

Napa County (707) 252-0313

DR. BRITTANY LEE GOSS D.O.

Internal Medicine (Rheumatology)

3273 CLAREMONT WAY, 209
NAPA, CA 94558

Napa County (707) 252-1035

DR. JASON T HUFFMAN M.D.

Orthopaedic Surgery (Orthopaedic Surgery of the Spine)

3273 CLAREMONT WAY, SUITE 100
NAPA, CA 94558

Napa County (707) 254-7117

NORTH BAY PROSTHETICS AND ORTHOTICS LLC

Prosthetic/Orthotic Supplier

3273 CLAREMONT WAY, SUITE 101
NAPA, CA 94558

Napa County (707) 254-7010

MIA ALARCON P.A.- C

Physician Assistant

3273 CLAREMONT WAY, SUITE 209
NAPA, CA 94558

Napa County (707) 252-1062

ANGELA DIANE GEASLIN OTR

Occupational Therapist

3273 CLAREMONT WAY
NAPA, CA 94558

Napa County (707) 259-1152

ADVENTIST HEALTH SILVERADO PSYCHIATRIC CLINIC

Specialist

3273 CLAREMONT WAY, SUITE 201
NAPA, CA 94558

Napa County (707) 252-1720

DR. DANIEL P BIRKBECK MD

Orthopaedic Surgery (Hand Surgery)

3273 CLAREMONT WAY, SUITE 100
NAPA, CA 94558

Napa County (707) 254-7117

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is John Diana's NPI number?

The NPI number for John Diana is 1649297540. It was assigned to this individual provider in the NPPES registry on July 16, 2006.

Where is John Diana located?

John Diana practices at 3273 Claremont Way Suite 100, Napa, CA 94558. The listed phone number is (707) 254-7117.

What is John Diana's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Adult Reconstructive Orthopaedic Surgery, with taxonomy code 207XS0114X.

Is John Diana enrolled in Medicare?

Yes. John Diana is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organizations bill Medicare for John Diana's services?

According to the CMS Revalidation Reassignment List (October 2026 release), John Diana reassigns Medicare benefits to 3 organizations: Adventist Health Physicians Network (Napa, CA), Napa Valley Orthopaedic Medical Group, Inc (Napa, CA) and St. Helena Hospital (Vallejo, CA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for John Diana's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for John Diana was last updated on October 22, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 12 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.