William Stuart Asch, M.D., PH.D.
Nephrology Physician · New Haven, CT
William Stuart Asch, M.D., PH.D. is a nephrology physician with a practice address in New Haven, Connecticut, and NPI 1003933326, issued on Mar 23, 2007. Check the license (Connecticut 044496, as entered in NPPES) on the Connecticut Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- William Stuart Asch
- Credential
- M.D., PH.D.
- Primary taxonomy
- Nephrology Physician 207RN0300X
- License number
- 044496 CT
Self-reported in NPPES; status is on the state search - Practice location
- 20 York Street CB 2041, New Haven, CT 06510
- Phone
- (203) 688-4748
- Enumerated
- Mar 23, 2007
- Record last updated
- Oct 27, 2007 (not updated in 19 years: call before relying on the address or phone)
- Fax
- (203) 688-4740
- Medicare enrollment
- Enrolled (PECOS I20081020000215); accepts Medicare assignment
- Medical or professional school
- State University Of New York At Stony Brook, School Of Medicine, 2001
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest nephrology physician records → All 167 in Connecticut → Look up another NPI →
Also registered at 20 York Street CB 2041
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Cindy Boutilier, APRNNurse Practitioner1710280136
Verify William Stuart Asch in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersConnecticut Medical Examining Board
Search for license 044496Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
26% more Medicare Part D claims than the average nephrology physician in 2024
1,841 Medicare Part D claims for 279 beneficiaries, against an average of 1,465 among the 10,986 providers of this specialty who prescribed in Part D. Brand-name drugs were 7% of claims. 14 claims were for opioids.
Most prescribed
- Prednisone256 claims
- Amlodipine Besylate135 claims
- Carvedilol118 claims
- Tamsulosin Hcl88 claims
- Sulfamethoxazole-Trimethoprim80 claims
- Metoprolol Tartrate66 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): 73.6 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.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Yale UniversityNew Haven, CT
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
William Stuart Asch among 167 nephrology physician records in Connecticut
William Stuart Asch, M.D., PH.D. is one of 167 nephrology physician records with a practice address in Connecticut. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 50% of them.
- NPI issued2007 · 50% of these records are older, 40% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 69% of these records are
- Graduated2001 · median 2002 among the 116 with a school on file
- Record last updated2007 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RN0300X and a Connecticut practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Nephrology Physician providers in Connecticut
There are 167 nephrology physician records in Connecticut.
All 167 in Connecticut → Every provider in New Haven → Nephrology Physician nationwide →
The 8 nephrology physician records with the nearest ZIP codes
- Robert Alpern, MDNew Haven, CT 065101477785285
- Justin Belcher, M.D.New Haven, CT 065101770773020
- Whitney Besse, M.D.New Haven, CT 065101285877704
- Ladan Golestaneh, MDNew Haven, CT 065101023199445
- Stephen Huot, MDNew Haven, CT 065101275518771
- Deepa Jayaram, M.D.New Haven, CT 065101316188055
- Abhishek Kumar, M.D.New Haven, CT 065101740431212
- Randy Luciano, M.D., PH.D.New Haven, CT 065101073786471
Common questions
What is William Stuart Asch, M.D., PH.D.'s NPI number?
William Stuart Asch, M.D., PH.D.'s National Provider Identifier (NPI) is 1003933326, issued on Mar 23, 2007. An NPI identifies a provider in billing; it is not a license.
Where is William Stuart Asch, M.D., PH.D. located?
The NPPES record lists a practice address at 20 York Street CB 2041, New Haven, CT, 06510. Phone: (203) 688-4748. Providers update this record themselves, so call before visiting.
How can I verify William Stuart Asch, M.D., PH.D.'s license?
NPPES lists Connecticut license number 044496, as entered by the provider. Search the Connecticut Medical Examining Board at https://www.elicense.ct.gov/Lookup/LicenseLookup.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does William Stuart Asch, M.D., PH.D. prescribe under Medicare Part D?
In 2024, William Stuart Asch, M.D., PH.D. had 1,841 Medicare Part D claims for 279 beneficiaries; the average among nephrology physician prescribers was 1,465. Part D covers Medicare prescriptions only.
What is William Stuart Asch, M.D., PH.D.'s MIPS final score?
The 2023 MIPS final score is 73.6 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.