Leah Ayn Mergen, PA-C
Physician Assistant · Sioux Falls, SD
Leah Ayn Mergen, PA-C is a physician assistant with a practice address in Sioux Falls, South Dakota, and NPI 1023389392, issued on Jan 19, 2012. Check the license (South Dakota 0799, as entered in NPPES) with the South Dakota board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Leah Ayn Mergen
- Credential
- PA-C
- Primary taxonomy
- Physician Assistant 363A00000X
- License number
- 0799 SD
Self-reported in NPPES; status is on the state search - Practice location
- 521 N Main Ave Ste 100, Sioux Falls, SD 57104
- Phone
- (605) 367-8214
- Enumerated
- Jan 19, 2012
- Record last updated
- Aug 29, 2017 (not updated in 9 years: call before relying on the address or phone)
- Medicaid IDs
- 6837110 SD
6837112 SD - Medicare enrollment
- Enrolled (PECOS I20120407000013); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 674 in South Dakota → Look up another NPI →
Also registered at 521 N Main Ave Ste 100
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Brittany LyleNurse Practitioner1659931822
Verify Leah Ayn Mergen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich South Dakota board licenses this profession
Search for license 0799Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.2 times the Medicare Part D claims of the average physician assistant in 2024
2,673 Medicare Part D claims for 234 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. 44 claims were for opioids.
Most prescribed
- Atorvastatin Calcium175 claims
- Levothyroxine Sodium131 claims
- Omeprazole108 claims
- Losartan Potassium98 claims
- Lisinopril90 claims
- Pantoprazole Sodium81 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.
Bills Medicare through one group practice
- Avera MckennanSioux Falls, SD
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Leah Ayn Mergen among 674 physician assistant records in South Dakota
Leah Ayn Mergen, PA-C is one of 674 physician assistant records with a practice address in South Dakota. 81% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2012, is newer than 48% of them.
- NPI issued2012 · 48% of these records are older, 50% newer
- In a Medicare fileYes · 81% of these records are
- In the CMS Doctors and Clinicians fileYes · 72% of these records are
- Graduated2011 · median 2014 among the 482 with a school on file
- Record last updated2017 · 53% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a South Dakota practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
245 physician assistant records list a practice address in Sioux Falls
They are 245 of the 6,563 NPPES records with a practice address in Sioux Falls, and 674 physician assistant records in South Dakota.
All 674 in South Dakota → Every provider in Sioux Falls → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Brett Bastian, PACSioux Falls, SD 571041043245467
- Renee Blaha, PA-CSioux Falls, SD 571041396700449
- Kathie Daak, PASioux Falls, SD 571041386640225
- Loran Frost, PASioux Falls, SD 571041619091287
- Michelle Healy, PA-CSioux Falls, SD 571041285663757
- Chelsey Kortan, PA-CSioux Falls, SD 571041083853162
- Ryan Krempges, PA CSioux Falls, SD 571041427074665
- Michael Noordsy, PA-CSioux Falls, SD 571041871590281
Common questions
What is Leah Ayn Mergen, PA-C's NPI number?
Leah Ayn Mergen, PA-C's National Provider Identifier (NPI) is 1023389392, issued on Jan 19, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Leah Ayn Mergen, PA-C located?
The NPPES record lists a practice address at 521 N Main Ave Ste 100, Sioux Falls, SD, 57104. Phone: (605) 367-8214. Providers update this record themselves, so call before visiting.
How can I verify Leah Ayn Mergen, PA-C's license?
NPPES lists South Dakota license number 0799, as entered by the provider. Search the South Dakota board that licenses this profession; the NPPES record confirms identity only.
How much does Leah Ayn Mergen, PA-C prescribe under Medicare Part D?
In 2024, Leah Ayn Mergen, PA-C had 2,673 Medicare Part D claims for 234 beneficiaries; the average among physician assistant prescribers was 830. 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.