WILLIAM J MAST FNP-C
NPI 1659089811
Nurse Practitioner - Family in Greenville, TX

Q: What is William Mast's NPI number?

The NPI number for William Mast is 1659089811. It was assigned to this individual provider in the NPPES registry on November 7, 2022.

Q: What is William Mast's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Family, with taxonomy code 363LF0000X.

Q: When was this NPI record last updated?

The NPPES record for William Mast was last updated on December 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months 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 November 07, 2022PECOS EnrolledAccepts Medicare Assignment

82.03/100

CMS Quality Rating

3900 JOE RAMSEY BLVD E STE 6, GREENVILLE, TX 75401(903) 455-1100(903) 455-1114 Get Directions Write a Review

NPPES record last updated: December 8, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Dec 8, 2025, Nov 7, 2022 (2 updates tracked since 2022).

On this page

About William J Mast Fnp-c NPPES

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

WILLIAM J MAST FNP-C (NPI 1659089811) is an individual family provider in Greenville, Texas, licensed in Texas (1098502) and active in the NPI registry since November 2022. He is enrolled in Medicare PECOS, is affiliated with Hunt Regional Medical Center, and is a graduate of Other (2022).

NPPES Registry Identity

NPI1659089811

Entity TypeIndividualMale

Primary Taxonomy363LF0000X

Provider Legal NameWILLIAM J MASTCredential: FNP-C

Location Address3900 JOE RAMSEY BLVD E STE 6Greenville, TX 75401-7705

Mailing Address1790 N Stonebridge DrMckinney, TX 75071-7437 · (972) 390-9002 · Fax (972) 984-7988

Phone(903) 455-1100

Fax(903) 455-1114

Sole ProprietorNo

Medical School CMSOtherGraduated 2022

Enumeration DateNovember 7, 2022

Last NPPES UpdateDecember 8, 20252 updates tracked since enumeration

NPPES CertifiedDecember 8, 2025

✔ NPI 1659089811 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyNurse Practitioner · FamilyPhysician Assistants & Advanced Practice Nursing Providers

Taxonomy Code363LF0000X

License✔ Licensed in TX · 1098502

3900 JOE RAMSEY BLVD E STE 6, Greenville, TX 75401

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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections and more.Insurance ›

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

William J Mast Fnp-c 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 ID3779952320

PECOS Enrollment IDI20221203000591

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 Mast reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Matthew D Barrows MD PA

35 mi

Dermatology

1790 N STONEBRIDGE DR
Mckinney, TX 75071

Reassigned Medicare billing, Texas enrollment
23 clinicians in this Medicare group

NPI 1699763490 (972) 390-9002

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 21

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.

Destruction of precancer skin growth, 2-14 growths 17003

This procedure involves removing 2-14 precancerous skin growths. The growths are treated to prevent them from potentially developing into skin cancer. The process is safe, with minimal discomfort, and promotes healthier skin.

2,557 services425 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.

1,064 services703 patients

Destruction of precancer skin growth, 1 growth 17000

"Destruction of precancer skin growth" is a procedure that eliminates a single precancerous skin growth. This is done to prevent it from developing into skin cancer. The growth may be removed using various methods such as cryotherapy (freezing), laser therapy, or topical medications.

1,013 services639 patients

Destruction of skin growth, 1-14 growths 17110

"Destruction of skin growth" refers to a procedure where 1-14 abnormal skin growths are removed. This is done using methods such as freezing, burning, or laser therapy. It helps prevent the growth from causing discomfort or turning into a more serious condition.

735 services521 patients

Biopsy of related skin growth, first growth 11102

A biopsy of a skin growth involves taking a small sample of the growth to examine it under a microscope. This helps determine if the growth is harmful. The procedure is typically quick, with minimal discomfort. It's a crucial step in ensuring your skin's health.

681 services549 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.

560 services426 patients

Biopsy of related skin growth, each additional growth 11103

A biopsy of related skin growth is a procedure where a small piece of skin growth is removed for testing. If additional growths are identified, they may also be biopsied. This helps in diagnosing skin conditions and planning appropriate treatment.

231 services165 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.

206 services206 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.

173 services145 patients

New patient office or other outpatient visit with straightforward medical decision making, if using time, 15 minutes or more 99202

This service involves an initial visit to the doctor's office or other outpatient setting. It typically lasts between 15-29 minutes. The doctor will review your medical history, conduct a physical examination, and discuss your health concerns. It's a chance to establish your health baseline and address any immediate medical issues.

114 services114 patients

Destruction of precancer skin growth, 15 or more growths 17004

This procedure involves removing 15 or more precancerous skin growths to prevent them from developing into cancer. It's done using various methods like freezing, creams, or minor surgery. The goal is to protect your health by stopping cancer before it starts.

63 services49 patients

Intermediate repair of wound of scalp, underarms, trunk, arms, or legs, 2.6-7.5 cm 12032

This procedure involves the repair of a wound between 2.6-7.5 cm located on the scalp, underarms, trunk, arms, or legs. The process includes cleaning, debridement (removal of damaged tissue), and suturing (stitching) of the wound to promote healing.

46 services44 patients

Simple or single drainage of skin abscess 10060

A simple or single drainage of skin abscess is a procedure to remove pus from a skin infection. A small cut is made on the abscess, the pus is drained out, and the area is cleaned. This helps to reduce pain, speed up recovery, and prevent the spread of infection.

43 services40 patients

Destruction of skin growth, 15 or more growths 17111

"Destruction of skin growth" refers to a procedure where unwanted skin growths, such as warts or moles, are removed. In this case, 15 or more growths are treated. Techniques may include freezing, burning, or laser therapy. It's a safe, quick process to improve skin health.

43 services33 patients

Biopsy of ear 69100

A biopsy of the ear is a medical procedure where a small sample of tissue is taken from your ear for examination. This helps doctors diagnose any abnormalities or diseases. It's a simple process, usually done under local anesthesia, and has minimal risks.

37 services35 patients

Removal of cancer skin growth of body, arms, or legs, 1.1-2.0 cm 11602

This procedure involves the surgical removal of a cancerous skin growth on the body, arms, or legs. The growth is between 1.1 and 2.0 cm in size. The goal is to eliminate cancer cells and prevent them from spreading to other parts of the body.

32 services32 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.

23 services23 patients

Punch biopsy, first skin growth 11104

A punch biopsy is a procedure where a small, circular tool is used to remove a sample of skin tissue. This is usually done to test a skin growth for potential issues. You may feel a pinch, but discomfort is minimal. The area heals quickly.

19 services17 patients

Destruction of cancer skin growth of trunk, arms, or legs, 1.1-2.0 cm 17262

This procedure involves removing a cancerous skin growth on the trunk, arms, or legs that is between 1.1 and 2.0 cm in size. The growth is destroyed using methods like surgery, laser, or freezing, aiming to eliminate cancer and prevent its spread.

18 services17 patients

Removal of noncancer skin growth of body, arms, or legs, 1.1-2.0 cm 11402

This procedure involves the removal of a noncancerous skin growth on the body, arms, or legs that is between 1.1 and 2.0 cm in size. It's a safe and routine procedure performed by a medical professional to improve your skin health and appearance.

14 services14 patients

Intermediate repair of wound of scalp, underarms, trunk, arms, or legs, 2.5 cm or less 12031

This procedure involves the repair of a wound that is located on the scalp, underarms, trunk, arms, or legs and is 2.5 cm or less in size. The repair is intermediate, meaning it's more complex than a simple closure, but not as extensive as a complex repair.

13 services12 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

Hunt Regional Medical Center

Acute Care Hospitals · Greenville, TX

3/5 CMS rating

OwnershipGovernment - Hospital District or Authority

CMS Certification Number450352

Location4215 Joe Ramsey Blvd EGreenville, TX 75401 · Hunt County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 75401 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

$84.92 typical visit price

range $54.84 – $166.88

Typical copayment $21.23 (range $13.71 – $41.72)

Most-billed visit code 99203

Established Patient

$97.05 typical visit price

range $17.52 – $136.11

Typical copayment $24.26 (range $4.38 – $34.02)

Most-billed visit code 99214

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.

82.03/100

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

Scored as part of a group practice

Quality

63.56

Promoting Interoperability

Improvement Activities

Cost

79.05

Reported Quality Measures

Advance Care Plan

19%1,996 patients1/55-star benchmark: 100%

Documentation of Current Medications in the Medical Record

74%5,995 patients1/55-star benchmark: 100%

Preventive Care and Screening: Unhealthy Alcohol Use: Screening & Brief Counseling

Patients combinedPopulations: 72% · 1,444 patients

Patients screened: 76% · 1,444 patients

23%92 patients

Provide Patients Electronic Access to Their Health Information

94%3,422 patients4/55-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

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

MADDISON DAVIS FNP-C

Nurse Practitioner (Family)

3900 JOE RAMSEY BLVD E STE 6
GREENVILLE, TX 75401

Hunt County (903) 455-1100

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 Mast's NPI number?

The NPI number for William Mast is 1659089811. It was assigned to this individual provider in the NPPES registry on November 7, 2022.

Where is William Mast located?

William Mast practices at 3900 Joe Ramsey Blvd E Ste 6, Greenville, TX 75401. The listed phone number is (903) 455-1100.

What is William Mast's specialty?

The primary specialty registered for this NPI is Nurse Practitioner, specializing in Family, with taxonomy code 363LF0000X.

Is William Mast enrolled in Medicare?

Yes. William Mast 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 organization bills Medicare for William Mast's services?

According to the CMS Revalidation Reassignment List (October 2026 release), William Mast reassigns Medicare benefits to Matthew D Barrows MD PA (Mckinney, TX). 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 Mast's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does William Mast accept?

Health plans from Ambetter Health, Ambetter from Arizona Complete Health, Ambetter from Arkansas Health & Wellness, Ambetter from Louisiana Healthcare Connections and Ambetter from Superior HealthPlan and 4 other insurers list William Mast as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is William Mast affiliated with any hospitals?

According to CMS data, William Mast is affiliated with Hunt Regional Medical Center.

When was this NPI record last updated?

The NPPES record for William Mast was last updated on December 8, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 10 months 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.