NPPES file of Aug 9, 2026

William Ray Mostow, M.D.

Emergency Medicine Physician · Sun City, AZ

William Ray Mostow, M.D. is an emergency medicine physician with a practice address in Sun City, Arizona, and NPI 1922057348, issued on May 10, 2006. Check the license (Arizona 26337, as entered in NPPES) on the Arizona Medical Board; the Medicare figures below come from public CMS files.

Record from CMS NPPES, file of Aug 9, 2026 · Medicare files 2023 and 2024 · method · Verify with CMS →

NPPES recordNPPES file of Aug 9, 2026
1922057348
Name
William Ray Mostow
Credential
M.D.
Primary taxonomy
Emergency Medicine Physician 207P00000X
License number
26337 AZ
Self-reported in NPPES; status is on the state search
Practice location
14502 West Meeker Boulevard, Sun City, AZ 85375
Phone
(623) 214-4000
Enumerated
May 10, 2006
Record last updated
Jan 14, 2009 (not updated in 17 years: call before relying on the address or phone)
Medicaid ID
428236 AZ
Medicare enrollment
Enrolled (PECOS I20060802000529); accepts Medicare assignment
Medical or professional school
Northwestern University Feinberg Medical School, 1989
Entity
Type 1 · individual
Public record from CMS NPPES (open it on the CMS NPI Registry). Enrollment, assignment, school and telehealth: CMS Doctors and Clinicians file, Aug 2026. A record is not a license: verify it with the state board.
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Also registered at 14502 West Meeker Boulevard

A shared address usually means a shared clinic or building; it does not show who employs whom.

  1. Aaron McKinney, M.D.Emergency Medicine Physician1043269467

Verify William Ray Mostow in five checks

  1. 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
  2. 2LicenseActive license and public ordersArizona Medical Board
    Search for license 26337
    Check the board
  3. 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
  4. 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
  5. 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Open the Arizona license search

PlainDoctor does not match the HHS-OIG exclusion list to individual records: most entries carry no NPI. Search the OIG exclusion list by name.

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65% fewer Medicare Part D claims than the average emergency medicine physician in 2024

80 Medicare Part D claims for 68 beneficiaries, against an average of 226 among the 54,106 providers of this specialty who prescribed in Part D. 13 claims were for opioids.

  1. William Mostow80
  2. Specialty average226

Most prescribed

  1. Cephalexin11 claims

Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.

The practice group's MIPS final score for 2023 (Medicare payment program): 76.1 of 100

The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.

  1. Qualityout of 100 · 30% of the final score69.4
  2. Costnot scored (reweighted)
  3. Promoting interoperabilitynot scored (reweighted)
  4. Improvement activities40 of 40 points · 15%100.0

Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).

Industry payments in 2024: $20.00

1 payment: education; the largest payer was Csl Behring. The 12,335 providers of this specialty with any payment received $953.79 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.

  1. William Mostow$20.00
  2. Specialty average$953.79

Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.

Bills Medicare through one group practice

  1. Cep America- Arizona, PCMesa, AZ

Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).

William Ray Mostow among 1,494 emergency medicine physician records in Arizona

William Ray Mostow, M.D. is one of 1,494 emergency medicine physician records with a practice address in Arizona. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 10% of them.

  • NPI issued2006 · 10% of these records are older, 62% newer
  • In a Medicare fileYes · 79% of these records are
  • In the CMS Doctors and Clinicians fileYes · 55% of these records are
  • Graduated1989 · median 2014 among the 828 with a school on file
  • Record last updated2009 · 55% of these records were not updated in five years or more

Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207P00000X and a Arizona practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).

22 emergency medicine physician records list a practice address in Sun City

They are 22 of the 813 NPPES records with a practice address in Sun City, and 1,494 emergency medicine physician records in Arizona.

The 8 emergency medicine physician records with the nearest ZIP codes

  1. Curtis Henderson, D.O.Sun City West, AZ 853751114977154
  2. Patricia Kahn, D.O.Sun City West, AZ 853751740210616
  3. Richard Lassiter, M.DSun City West, AZ 853751376593780
  4. Christopher McCabe, MDSun City West, AZ 853751316470933
  5. Jay McCombs, D.O.Sun City West, AZ 853751669634689
  6. Aaron McKinney, M.D.Sun City, AZ 853751043269467
  7. Toyo Trenou, D.O.Sun City West, AZ 853751083913826
  8. Marie Dowling, MDSurprise, AZ 853741073717732

Common questions

What is William Ray Mostow, M.D.'s NPI number?

William Ray Mostow, M.D.'s National Provider Identifier (NPI) is 1922057348, issued on May 10, 2006. An NPI identifies a provider in billing; it is not a license.

Where is William Ray Mostow, M.D. located?

The NPPES record lists a practice address at 14502 West Meeker Boulevard, Sun City, AZ, 85375. Phone: (623) 214-4000. Providers update this record themselves, so call before visiting.

How can I verify William Ray Mostow, M.D.'s license?

NPPES lists Arizona license number 26337, as entered by the provider. Search the Arizona Medical Board at https://www.azmd.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.

How much does William Ray Mostow, M.D. prescribe under Medicare Part D?

In 2024, William Ray Mostow, M.D. had 80 Medicare Part D claims for 68 beneficiaries; the average among emergency medicine physician prescribers was 226. Part D covers Medicare prescriptions only.

What is William Ray Mostow, M.D.'s MIPS final score?

The 2023 MIPS final score is 76.1 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.