Britni Souther Mashni, DO
Hematology & Oncology Physician · Grand Rapids, MI
Britni Souther Mashni, DO is a hematology & oncology physician with a practice address in Grand Rapids, Michigan, and NPI 1972996544, issued on Mar 6, 2015. Check the license (Michigan 5101021760, as entered in NPPES) on the Michigan Board of Medicine (LARA); the Medicare figures below come from public CMS files.
- Name
- Britni Souther Mashni
- Credential
- DO
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- 5101021760 MI
Self-reported in NPPES; status is on the state search - Practice location
- 250 Cherry St SE Ste 2200, Grand Rapids, MI 49503
- Phone
- (616) 685-5600
- Enumerated
- Mar 6, 2015
- Record last updated
- Jul 7, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20190815002519); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 340 in Michigan → Look up another NPI →
Also registered at 250 Cherry St SE Ste 2200
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Marlee Bogema, FNPFamily Nurse Practitioner1396398236
- Kelly Decker, LMSWClinical Social Worker1013516533
- Kristen George, LMSWClinical Social Worker1952824328
- Elizabeth Heyboer, PA-CPhysician Assistant1912936378
- Shannon Iakiri, N.P.Family Nurse Practitioner1821021098
- Lauren Jongsma, NPGerontology Nurse Practitioner1508428897
Verify Britni Souther Mashni in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMichigan Board of Medicine (LARA)
Search for license 5101021760Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% more Medicare Part D claims than the average hematology & oncology physician in 2024
1,748 Medicare Part D claims for 312 beneficiaries, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D. Brand-name drugs were 22% of claims. 33 claims were for opioids.
Most prescribed
- Anastrozole258 claims
- Acyclovir218 claims
- Hydroxyurea115 claims
- Dexamethasone82 claims
- Venclexta81 claims
- Prochlorperazine Maleate62 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): 89.9 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).
Industry payments in 2024: $1,727.26
89 payments; by number, the most common kind was food and beverage; the largest payer was GlaxoSmithKline, LLC. The 8,560 providers of this specialty with any payment received $7,481.41 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
- Cancer And Hematology Centers OF Western MI, P.C.Holland, MI
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Britni Souther Mashni among 340 hematology & oncology physician records in Michigan
Britni Souther Mashni, DO is one of 340 hematology & oncology 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 2015, is newer than 73% of them.
- NPI issued2015 · 73% of these records are older, 24% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 61% of these records are
- Graduated2015 · median 2004 among the 206 with a school on file
- Record last updated2021 · 52% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RH0003X and a Michigan practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in Michigan
There are 340 hematology & oncology physician records in Michigan.
All 340 in Michigan → Every provider in Grand Rapids → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Mohammad Alhyari, MDGrand Rapids, MI 495031346554912
- Brett Brinker, MDGrand Rapids, MI 495031750347290
- Sreenivasa Chandana, MDGrand Rapids, MI 495031972705838
- Stephanie Dublis, D.O.Grand Rapids, MI 495031346443769
- Thomas Gribbin, M.D.Grand Rapids, MI 495031639179286
- Colin Hardin, M.D.Grand Rapids, MI 495031639459860
- Daniel Isaac, D.O.Grand Rapids, MI 495031326486416
- Timothy O'Rourke, M.D.Grand Rapids, MI 495031215938303
Common questions
What is Britni Souther Mashni, DO's NPI number?
Britni Souther Mashni, DO's National Provider Identifier (NPI) is 1972996544, issued on Mar 6, 2015. An NPI identifies a provider in billing; it is not a license.
Where is Britni Souther Mashni, DO located?
The NPPES record lists a practice address at 250 Cherry St SE Ste 2200, Grand Rapids, MI, 49503. Phone: (616) 685-5600. Providers update this record themselves, so call before visiting.
How can I verify Britni Souther Mashni, DO's license?
NPPES lists Michigan license number 5101021760, 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 Britni Souther Mashni, DO prescribe under Medicare Part D?
In 2024, Britni Souther Mashni, DO had 1,748 Medicare Part D claims for 312 beneficiaries; the average among hematology & oncology physician prescribers was 877. Part D covers Medicare prescriptions only.
What is Britni Souther Mashni, DO's MIPS final score?
The 2023 MIPS final score is 89.9 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.