Gregory H. Downer, M.D.
Nephrology Physician · Muskegon, MI
Gregory H. Downer, M.D. is a nephrology physician with a practice address in Muskegon, Michigan, and NPI 1285635367, issued on Aug 10, 2005. Check the license (Michigan 4301048039, as entered in NPPES) on the Michigan Board of Medicine (LARA); the Medicare figures below come from public CMS files.
- Name
- Gregory H. Downer
- Credential
- M.D.
- Primary taxonomy
- Nephrology Physician 207RN0300X
- License number
- 4301048039 MI
Self-reported in NPPES; status is on the state search - Practice location
- 1250 Mercy Dr, Muskegon, MI 49444
- Phone
- (231) 733-1912
- Enumerated
- Aug 10, 2005
- Record last updated
- Feb 17, 2014 (not updated in 12 years: call before relying on the address or phone)
- Fax
- (231) 737-4603
- Medicaid ID
- 1816250 MI
- Medicare enrollment
- Enrolled (PECOS I20100728000564); accepts Medicare assignment
- Medical or professional school
- Indiana University School Of Medicine, 1981
- Entity
- Type 1 · individual
8 nearest nephrology physician records → All 376 in Michigan → Look up another NPI →
Also registered at 1250 Mercy Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Mark Staniforth, MDNephrology Physician1619978707
Verify Gregory H. Downer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMichigan Board of Medicine (LARA)
Search for license 4301048039Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
9% fewer Medicare Part D claims than the average nephrology physician in 2024
1,332 Medicare Part D claims for 398 beneficiaries, against an average of 1,465 among the 10,986 providers of this specialty who prescribed in Part D. Brand-name drugs were 22% of claims.
Most prescribed
- Farxiga102 claims
- Amlodipine Besylate85 claims
- Torsemide71 claims
- Lisinopril68 claims
- Losartan Potassium67 claims
- Potassium Chloride62 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.
Industry payments in 2024: $27.32
1 payment: food and beverage; the largest payer was Travere Therapeutics, Inc. The 8,230 providers of this specialty with any payment received $3,091.37 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
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
- West Michigan Nephrology PLLCMuskegon, MI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gregory H. Downer among 376 nephrology physician records in Michigan
Gregory H. Downer, M.D. is one of 376 nephrology physician records with a practice address in Michigan. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 88% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 74% of these records are
- Graduated1981 · median 2001 among the 279 with a school on file
- Record last updated2014 · 59% 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 Michigan practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Nephrology Physician providers in Michigan
There are 376 nephrology physician records in Michigan.
All 376 in Michigan → Every provider in Muskegon → Nephrology Physician nationwide →
The 8 nephrology physician records with the nearest ZIP codes
- James Conley, M.D.Muskegon, MI 494441639137086
- Emily Conley, M.D.Muskegon, MI 494441891753224
- Yumiko Knudson, MDMuskegon, MI 494441932100021
- Barry Kram, D.O.Muskegon, MI 494441508863457
- Joseph McKenna, M.D.Muskegon, MI 494441760411599
- Randall Muir, D.OMuskegon, MI 494441942620521
- Mark Staniforth, MDMuskegon, MI 494441619978707
- Bao-Min Twu, MDMuskegon, MI 494441356342448
Common questions
What is Gregory H. Downer, M.D.'s NPI number?
Gregory H. Downer, M.D.'s National Provider Identifier (NPI) is 1285635367, issued on Aug 10, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Gregory H. Downer, M.D. located?
The NPPES record lists a practice address at 1250 Mercy Dr, Muskegon, MI, 49444. Phone: (231) 733-1912. Providers update this record themselves, so call before visiting.
How can I verify Gregory H. Downer, M.D.'s license?
NPPES lists Michigan license number 4301048039, as entered by the provider. Search the Michigan Board of Medicine (LARA) at https://aca-prod.accela.com/MILARA/GeneralProperty/PropertyLookUp.aspx?isLicensee=Y&TabName=APO. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gregory H. Downer, M.D. prescribe under Medicare Part D?
In 2024, Gregory H. Downer, M.D. had 1,332 Medicare Part D claims for 398 beneficiaries; the average among nephrology physician prescribers was 1,465. Part D covers Medicare prescriptions only.
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.