Tammy A. O'Brien, M.D.
Family Medicine Physician · Cedar Rapids, IA
Tammy A. O'Brien, M.D. is a family medicine physician with a practice address in Cedar Rapids, Iowa, and NPI 1184703571, issued on Nov 4, 2006. Check the license (Iowa 31465, as entered in NPPES) on the Iowa Board of Medicine; the Medicare figures below come from public CMS files.
- Name
- Tammy A. O'Brien
- Credential
- M.D.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License number
- 31465 IA
Self-reported in NPPES; status is on the state search - Practice location
- 500 8TH Ave SE, Cedar Rapids, IA 52401
- Phone
- (319) 364-8704
- Enumerated
- Nov 4, 2006
- Record last updated
- Jul 25, 2023
- Fax
- (319) 365-7747
- Medicaid ID
- 1170308 IA
- Medicare enrollment
- Enrolled (PECOS I20100302000679); accepts Medicare assignment
- Medical or professional school
- University Of Iowa, Rj & L Carver College Of Medicine, 1995
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 2,336 in Iowa → Look up another NPI →
Also registered at 500 8TH Ave SE
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Nancy Angenend, M.D.Family Medicine Physician1649359035
- Chad Davis, P.A. - CPhysician Assistant1073692463
- Katie Dunbar, D.O.Family Medicine Physician1104213107
- Jill Flory, M.D.Family Medicine Physician1811076201
- Katherine Hopper, MDFamily Medicine Physician1598080145
- Carla Schulz, M.D.Family Medicine Physician1740369131
Verify Tammy A. O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersIowa Board of Medicine
Search for license 31465Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2% more Medicare Part D claims than the average family medicine physician in 2024
3,624 Medicare Part D claims for 265 beneficiaries, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 9% of claims. 209 claims were for opioids.
Most prescribed
- Levothyroxine Sodium278 claims
- Atorvastatin Calcium136 claims
- Gabapentin102 claims
- Hydrocodone-Acetaminophen98 claims
- Lisinopril88 claims
- Ozempic88 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): 80.9 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 one group practice
- Family Medicine Specialists PCCedar Rapids, IA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Tammy A. O'Brien among 2,336 family medicine physician records in Iowa
Tammy A. O'Brien, M.D. is one of 2,336 family medicine physician records with a practice address in Iowa. 75% 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 16% of them.
- NPI issued2006 · 16% of these records are older, 48% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated1995 · median 2006 among the 1,367 with a school on file
- Record last updated2023 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a Iowa practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
97 family medicine physician records list a practice address in Cedar Rapids
They are 97 of the 2,949 NPPES records with a practice address in Cedar Rapids, and 2,336 family medicine physician records in Iowa.
All 2,336 in Iowa → Every provider in Cedar Rapids → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Nancy Angenend, M.D.Cedar Rapids, IA 524011649359035
- Gordon Baustian, M.D.Cedar Rapids, IA 524011558349589
- Jennifer Beck, M.D.Cedar Rapids, IA 524011053375022
- Valerie Crowther Besset, M.D.Cedar Rapids, IA 524011316094683
- Jill Flory, M.D.Cedar Rapids, IA 524011811076201
- Jennifer Lickteig, MDCedar Rapids, IA 524011801856091
- Maureen Marks, M.D.Cedar Rapids, IA 524011659389260
- Tony Myers, M.D.Cedar Rapids, IA 524011407835283
Common questions
What is Tammy A. O'Brien, M.D.'s NPI number?
Tammy A. O'Brien, M.D.'s National Provider Identifier (NPI) is 1184703571, issued on Nov 4, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Tammy A. O'Brien, M.D. located?
The NPPES record lists a practice address at 500 8TH Ave SE, Cedar Rapids, IA, 52401. Phone: (319) 364-8704. Providers update this record themselves, so call before visiting.
How can I verify Tammy A. O'Brien, M.D.'s license?
NPPES lists Iowa license number 31465, as entered by the provider. Search the Iowa Board of Medicine at https://dial.iowa.gov/about-dial/boards-and-commissions/medicine. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Tammy A. O'Brien, M.D. prescribe under Medicare Part D?
In 2024, Tammy A. O'Brien, M.D. had 3,624 Medicare Part D claims for 265 beneficiaries; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
What is Tammy A. O'Brien, M.D.'s MIPS final score?
The 2023 MIPS final score is 80.9 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.