Mallory Langell Sievers, PA-C
Physician Assistant · Castaic, CA
Mallory Langell Sievers, PA-C is a physician assistant with a practice address in Castaic, California, and NPI 1902379548, issued on Jan 7, 2019. Check the license with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Mallory Langell Sievers
- Credential
- PA-C
- Primary taxonomy
- Physician Assistant 363A00000X
- Practice location
- 28253 Branch RD, Castaic, CA 91384
- Phone
- (661) 803-3654
- Enumerated
- Jan 7, 2019
- Record last updated
- Aug 13, 2019 (not updated in 7 years: call before relying on the address or phone)
- Medicare enrollment
- Enrolled (PECOS I20190910003187); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 14,451 in California → Look up another NPI →
Verify Mallory Langell Sievers in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this professionCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
89% fewer Medicare Part D claims than the average physician assistant in 2024
94 Medicare Part D claims for 65 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D.
Most prescribed
- Fluticasone Propionate28 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): 85.7 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
- Cedars-Sinai Medical Care FoundationLos Angeles, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Mallory Langell Sievers among 14,451 physician assistant records in California
Mallory Langell Sievers, PA-C is one of 14,451 physician assistant records with a practice address in California. 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 2019, is newer than 56% of them.
- NPI issued2019 · 56% of these records are older, 38% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 50% of these records are
- Graduated2018 · median 2018 among the 7,214 with a school on file
- Record last updated2019 · 40% 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 California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
2 physician assistant records list a practice address in Castaic
They are 2 of the 95 NPPES records with a practice address in Castaic, and 14,451 physician assistant records in California.
All 14,451 in California → Every provider in Castaic → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Robert Mena, PACastaic, CA 913841730810672
- Mai Engelberg, PA-CCanyon Country, CA 913871467349654
- Zolissa Fernando, PA-CSanta Clarita, CA 913871528095866
- Tia Littleford, PA-CStevenson Ranch, CA 913811770175572
- Allison Player, PA-CCanyon Country, CA 913871700445699
- Gunbir Rana, PA-CStevenson Ranch, CA 913811346612546
- Taelor YoungOak Park, CA 913771073150744
- Lili Barajas, PA-CVan Nuys, CA 914011144995465
Common questions
What is Mallory Langell Sievers, PA-C's NPI number?
Mallory Langell Sievers, PA-C's National Provider Identifier (NPI) is 1902379548, issued on Jan 7, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Mallory Langell Sievers, PA-C located?
The NPPES record lists a practice address at 28253 Branch RD, Castaic, CA, 91384. Phone: (661) 803-3654. Providers update this record themselves, so call before visiting.
How can I verify Mallory Langell Sievers, PA-C's license?
Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Mallory Langell Sievers, PA-C prescribe under Medicare Part D?
In 2024, Mallory Langell Sievers, PA-C had 94 Medicare Part D claims for 65 beneficiaries; the average among physician assistant prescribers was 830. Part D covers Medicare prescriptions only.
What is Mallory Langell Sievers, PA-C's MIPS final score?
The 2023 MIPS final score is 85.7 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.