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WILLIAM G STONE MD
NPI 1255505764
Surgery in Sonora, CA

Active since April 15, 2008PECOS Enrolled
82.28/100
CMS Quality Rating
900 GREENLEY RD, SONORA, CA 95370(605) 593-3688 Get Directions Write a Review

NPPES record last updated: April 30, 2022. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Apr 30, 2022, Aug 13, 2020, Sep 23, 2019 and 1 more (4 updates tracked since 2016).

About William G Stone Md NPPES

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

WILLIAM G STONE MD (NPI 1255505764) is an individual surgery provider in Sonora, California, licensed in California (C167208) and active in the NPI registry since April 2008. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1255505764
Entity TypeIndividualMale
Primary Taxonomy208600000X
Provider Legal NameWILLIAM G STONECredential: MD
Location Address900 GREENLEY RDSonora, CA 95370-5287
Mailing Address18200 Old Wards Ferry RoadSonora, CA 95370
Phone(605) 593-3688
Sole ProprietorNo
Enumeration DateApril 15, 2008
Last NPPES UpdateApril 30, 20224 updates tracked since enumeration
NPPES CertifiedApril 30, 2022
✔ NPI 1255505764 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySurgeryAllopathic & Osteopathic Physicians
Taxonomy Code208600000X
Licenses✔ Licensed in CA · C167208✔ Licensed in SD · 8495
Definition
A general surgeon has expertise related to the diagnosis - preoperative, operative and postoperative management - and management of complications of surgical conditions in the following areas: alimentary tract; abdomen; breast, skin and soft tissue; endocrine system; head and neck surgery; pediatric surgery; surgical critical care; surgical oncology; trauma and burns; and vascular surgery. General surgeons increasingly provide care through the use of minimally invasive and endoscopic techniques. Many general surgeons also possess expertise in transplantation surgery, plastic surgery and cardiothoracic surgery.
900 GREENLEY RD, Sonora, CA 95370
Open in Google Maps ↗

Medicare Participation & PECOS CMS

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

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

William G Stone Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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 Reassignment

Medicare enrollment records show William Stone reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Surgical Solutions Professional Limited Liability Company
986 mi
Surgery
211 FOUNDERS PARK DR STE B
Rapid City, SD 57701
  • Reassigned Medicare billing, South Dakota enrollment
  • 2 clinicians in this Medicare group
NPI 1124410584 (605) 791-5553

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 4

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.

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
50 services32 patients
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223
Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.
41 services40 patients
Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 99222
Initial hospital inpatient care is a service where a healthcare provider spends about 50 minutes per day overseeing your care while you're admitted in the hospital. This includes reviewing your health status, planning your treatment, and ensuring your safety and comfort.
36 services34 patients
Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes 99231
Follow-up hospital inpatient care is a daily service where a healthcare professional checks on your health progress during your hospital stay. Each session typically lasts 15 minutes, involving updates on your condition and adjustments to your treatment plan, if necessary.
30 services21 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 95370 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient
$90.32 typical visit price
range $58.87 – $176.60
Typical copayment $22.58 (range $14.71 – $44.15)
Most-billed visit code 99203
Established Patient
$73.16 typical visit price
range $19.28 – $144.60
Typical copayment $18.29 (range $4.82 – $36.15)
Most-billed visit code 99213
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

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.

82.28/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored as part of a group practice
Quality88.81
Promoting Interoperability99
Improvement Activities40
Cost52.95

Reported Quality Measures

Breast Cancer Screening
Percentage of women 50-74 years of age who had a mammogram to screen for breast cancer
62%61 patients3/55-star benchmark: 92%
Closing the Referral Loop: Receipt of Specialist Report
Percentage of patients with referrals, regardless of age, for which the referring provider receives a report from the provider to whom the patient was referred
76%29 patients4/55-star benchmark: 95%
Colorectal Cancer Screening
Percentage of adults 50-75 years of age who had appropriate screening for colorectal cancer
56%125 patients3/55-star benchmark: 85%
Documentation of Current Medications in the Medical Record
Percentage of visits for patients aged 18 years and older for which the eligible professional or eligible clinician attests to documenting a list of current medications using all immediate resources available on the date of the encounter.
95%551 patients4/55-star benchmark: 100%
Pneumococcal Vaccination Status for Older Adults
Percentage of patients 65 years of age and older who have ever received a pneumococcal vaccine
56%93 patients3/55-star benchmark: 90%
Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan
Percentage of patients aged 18 years and older with a BMI documented during the current encounter or during the previous twelve months AND with a BMI outside of normal parameters, a follow-up plan is documented during the encounter or during the previous…
21%287 patients1/55-star benchmark: 97%
Preventive Care and Screening: Influenza Immunization
Percentage of patients aged 6 months and older seen for a visit between October 1 and March 31 who received an influenza immunization OR who reported previous receipt of an influenza immunization
82%73 patients4/55-star benchmark: 88%
Preventive Care and Screening: Tobacco Use: Screening and Cessation Intervention
Percentage of patients aged 18 years and older who were screened for tobacco use one or more times within 24 months AND who received tobacco cessation intervention if identified as a tobacco user
Patients tobacco: 90% · 39 patients
95%39 patients
Use of High-Risk Medications in the Elderly
Percentage of patients 65 years of age and older who were ordered high-risk medications. Two rates are submitted. 1) Percentage of patients who were ordered at least one high-risk medication.
Lower rates are better for this measure.
Patients 2+: 0% · 93 patients
0%93 patients5/55-star benchmark: 100%
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 16

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

SONORA COMMUNITY HOSPITAL
Internal Medicine (Cardiovascular Disease)
900 GREENLEY RD, SUITE 911
SONORA, CA 95370
Tuolumne County (209) 532-0511
MR. EDMAN FUENTES PAC
Physician Assistant (Surgical)
900 GREENLEY RD, SUITE 914
SONORA, CA 95370
Tuolumne County (925) 469-6274
DR. KEVIN A. ORCA PHARM.D.
Pharmacist
900 GREENLEY RD, STE 912
SONORA, CA 95370
Tuolumne County (209) 536-3700
JAMES LEONARD COMAZZI M.D.
Specialist
900 GREENLEY RD, SUITE 911
SONORA, CA 95370
Tuolumne County (209) 532-0511
MRS. JOANNE LINDA RIOS CNS
Clinical Nurse Specialist
900 GREENLEY RD, SUITE 905
SONORA, CA 95370
Tuolumne County (209) 536-3720
SHALOM EUGENE MARGOLIS M.D.
Specialist
900 GREENLEY RD, SUITE 911
SONORA, CA 95370
Tuolumne County (209) 532-0511
MEREDITH R MCBRIDE MD
Surgery (Vascular Surgery)
900 GREENLEY RD, SUITE 923
SONORA, CA 95370
Tuolumne County (209) 536-5090
ONCOLOGY GROUP INC.
Radiology (Radiation Oncology)
900 GREENLEY RD, SUITE 901
SONORA, CA 95370
Tuolumne County (209) 536-0223

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 William Stone's NPI number?

The NPI number for William Stone is 1255505764. It was assigned to this individual provider in the NPPES registry on April 15, 2008.

Where is William Stone located?

William Stone practices at 900 Greenley Rd, Sonora, CA 95370. The listed phone number is (605) 593-3688.

What is William Stone's specialty?

The primary specialty registered for this NPI is Surgery with taxonomy code 208600000X.

Is William Stone enrolled in Medicare?

Yes. William Stone is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for William Stone's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Stone reassigns Medicare benefits to Surgical Solutions Professional Limited Liability Company (Rapid City, SD). The 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 William Stone'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 William Stone was last updated on April 30, 2022. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 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.