Erin Jo Mercer Terpstra, MD, PHD
Internal Medicine Physician · Sioux Falls, SD
Erin Jo Mercer Terpstra, MD, PHD is an internal medicine physician with a practice address in Sioux Falls, South Dakota, and NPI 1366005662, issued on Apr 22, 2019. Check the license (South Dakota 13919, as entered in NPPES) on the South Dakota Board of Medical and Osteopathic Examiners; the Medicare figures below come from public CMS files.
- Name
- Erin Jo Mercer Terpstra
- Credential
- MD, PHD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- 13919 SD
Self-reported in NPPES; status is on the state search - Practice location
- 1321 W 22ND St, Sioux Falls, SD 57105
- Phone
- (605) 404-4000
- Enumerated
- Apr 22, 2019
- Record last updated
- Dec 20, 2022
- Medicaid ID
- 390200000X SD
- Medicare enrollment
- Enrolled (PECOS I20221228003129); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 247 in South Dakota → Look up another NPI →
Also registered at 1321 W 22ND St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Erin Jo Mercer Terpstra in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersSouth Dakota Board of Medical and Osteopathic Examiners
Search for license 13919Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
39% more Medicare Part D claims than the average internal medicine physician in 2024
4,427 Medicare Part D claims for 413 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. 192 claims were for opioids.
Most prescribed
- Atorvastatin Calcium234 claims
- Levothyroxine Sodium228 claims
- Omeprazole161 claims
- Rosuvastatin Calcium159 claims
- Losartan Potassium135 claims
- Lisinopril126 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): 76.7 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
- Sanford Medical CenterSioux Falls, SD
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Erin Jo Mercer Terpstra among 247 internal medicine physician records in South Dakota
Erin Jo Mercer Terpstra, MD, PHD is one of 247 internal medicine physician records with a practice address in South Dakota. 79% 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 86% of them.
- NPI issued2019 · 86% of these records are older, 11% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 59% of these records are
- Graduated2019 · median 2008 among the 146 with a school on file
- Record last updated2022 · 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 207R00000X and a South Dakota practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
110 internal medicine physician records list a practice address in Sioux Falls
They are 110 of the 6,563 NPPES records with a practice address in Sioux Falls, and 247 internal medicine physician records in South Dakota.
All 247 in South Dakota → Every provider in Sioux Falls → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Paul Aspaas, M.D.Sioux Falls, SD 571051215932116
- Robert Behrend, MDSioux Falls, SD 571051578569000
- Emad Beshai, M.D.Sioux Falls, SD 571051528069598
- Allen Funk, M.D.Sioux Falls, SD 571051306841291
- Gregory Geise, MDSioux Falls, SD 571051144221938
- Timothy Hurley, M.D.Sioux Falls, SD 571051194720623
- Eric Larson, M.D.Sioux Falls, SD 571051134124019
- David Nelson, M.D.Sioux Falls, SD 571051538164066
Common questions
What is Erin Jo Mercer Terpstra, MD, PHD's NPI number?
Erin Jo Mercer Terpstra, MD, PHD's National Provider Identifier (NPI) is 1366005662, issued on Apr 22, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Erin Jo Mercer Terpstra, MD, PHD located?
The NPPES record lists a practice address at 1321 W 22ND St, Sioux Falls, SD, 57105. Phone: (605) 404-4000. Providers update this record themselves, so call before visiting.
How can I verify Erin Jo Mercer Terpstra, MD, PHD's license?
NPPES lists South Dakota license number 13919, as entered by the provider. Search the South Dakota Board of Medical and Osteopathic Examiners at https://www.sdbmoe.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Erin Jo Mercer Terpstra, MD, PHD prescribe under Medicare Part D?
In 2024, Erin Jo Mercer Terpstra, MD, PHD had 4,427 Medicare Part D claims for 413 beneficiaries; the average among internal medicine physician prescribers was 3,176. Part D covers Medicare prescriptions only.
What is Erin Jo Mercer Terpstra, MD, PHD's MIPS final score?
The 2023 MIPS final score is 76.7 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.