Frederick B. Hernaez, MD
Internal Medicine Physician · Marshfield, WI
Frederick B. Hernaez, MD is an internal medicine physician with a practice address in Marshfield, Wisconsin, and NPI 1205498227, issued on Jun 29, 2019. Check the license (Wisconsin 74654, as entered in NPPES) on the Wisconsin Medical Examining Board; the Medicare figures below come from public CMS files.
- Name
- Frederick B. Hernaez
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 74654 WI
Self-reported in NPPES; status is on the state search - Practice location
- 1000 N Oak Ave, Marshfield, WI 54449
- Phone
- (715) 387-5511
- Enumerated
- Jun 29, 2019
- Record last updated
- Apr 23, 2024
- Medicare enrollment
- Enrolled (PECOS I20231002000793); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 2,078 in Wisconsin → Look up another NPI →
Also registered at 1000 N Oak Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Frederick B. Hernaez in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWisconsin Medical Examining Board
Search for license 74654Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
4% fewer Medicare Part D claims than the average internal medicine physician in 2024
3,058 Medicare Part D claims for 322 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 15% of claims. 138 claims were for opioids.
Most prescribed
- Atorvastatin Calcium243 claims
- Levothyroxine Sodium123 claims
- Lisinopril112 claims
- Gabapentin107 claims
- Amlodipine Besylate100 claims
- Omeprazole96 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): 78.9 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 2 group practices
- Mchs Hospitals IncMarshfield, WI
- Memorial Hospital IncNeillsville, WI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Frederick B. Hernaez among 2,078 internal medicine physician records in Wisconsin
Frederick B. Hernaez, MD is one of 2,078 internal medicine physician records with a practice address in Wisconsin. 70% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2019, is newer than 81% of them.
- NPI issued2019 · 81% of these records are older, 16% newer
- In a Medicare fileYes · 70% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated2017 · median 2002 among the 1,098 with a school on file
- Record last updated2024 · 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 207R00000X and a Wisconsin practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
62 internal medicine physician records list a practice address in Marshfield
They are 62 of the 1,360 NPPES records with a practice address in Marshfield, and 2,078 internal medicine physician records in Wisconsin.
All 2,078 in Wisconsin → Every provider in Marshfield → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Linda Daly-Oneill, MDMarshfield, WI 544491366550386
- Gaojun Gui, MDMarshfield, WI 544491568570828
- Tula Haldes, MDMarshfield, WI 544491942318969
- Muhammad Haleem, MDMarshfield, WI 544491275544546
- Renee Hoynacke, MDMarshfield, WI 544491821106832
- Ewa Kubica, MDMarshfield, WI 544491942318951
- Urszula Moldysz, MDMarshfield, WI 544491538279682
- Douglas Peterson, MDMarshfield, WI 544491437267440
Common questions
What is Frederick B. Hernaez, MD's NPI number?
Frederick B. Hernaez, MD's National Provider Identifier (NPI) is 1205498227, issued on Jun 29, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Frederick B. Hernaez, MD located?
The NPPES record lists a practice address at 1000 N Oak Ave, Marshfield, WI, 54449. Phone: (715) 387-5511. Providers update this record themselves, so call before visiting.
How can I verify Frederick B. Hernaez, MD's license?
NPPES lists Wisconsin license number 74654, as entered by the provider. Search the Wisconsin Medical Examining Board at https://dsps.wi.gov/Pages/BoardsCouncils/MEB/Default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Frederick B. Hernaez, MD prescribe under Medicare Part D?
In 2024, Frederick B. Hernaez, MD had 3,058 Medicare Part D claims for 322 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Frederick B. Hernaez, MD's MIPS final score?
The 2023 MIPS final score is 78.9 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.