Karen Lynn Darkenwald, O.D.
Optometrist · Sacramento, CA
Karen Lynn Darkenwald, O.D. is an optometrist with a practice address in Sacramento, California, and NPI 1124177183, issued on Jan 9, 2007. Check the license (California 8449T, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Karen Lynn Darkenwald
- Credential
- O.D.
- Primary taxonomy
- Optometrist 152W00000X
- License number
- 8449T CA
Self-reported in NPPES; status is on the state search - Practice location
- 1650 Response RD, Sacramento, CA 95815
- Phone
- (916) 614-4015
- Enumerated
- Jan 9, 2007
- Record last updated
- Jan 27, 2022
- Medicare enrollment
- Enrolled (PECOS I20120926000489); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest optometrist records → All 8,308 in California → Look up another NPI →
Also registered at 1650 Response RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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Verify Karen Lynn Darkenwald in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 8449TCheck the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
74% fewer Medicare Part D claims than the average optometrist in 2024
73 Medicare Part D claims for 48 beneficiaries, against an average of 277 among the 33,128 providers of this specialty who prescribed in Part D. Brand-name drugs were 37% of claims.
Most prescribed
- Cyclosporine25 claims
- Erythromycin22 claims
- Neomycin-Polymyxin-Dexameth16 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
- Permanente Medical Group IncSanta Clara, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Karen Lynn Darkenwald among 8,308 optometrist records in California
Karen Lynn Darkenwald, O.D. is one of 8,308 optometrist records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 34% of them.
- NPI issued2007 · 34% of these records are older, 46% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileYes · 43% of these records are
- Graduated1986 · median 2008 among the 3,573 with a school on file
- Record last updated2022 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 152W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Optometrist providers in California
There are 8,308 optometrist records in California.
All 8,308 in California → Every provider in Sacramento → Optometrist nationwide →
The 8 optometrist records with the nearest ZIP codes
- Selina Chan, O.D.Sacramento, CA 958151225117286
- John Corpus, ODSacramento, CA 958151902829336
- Taz Curtis, O.D.Sacramento, CA 958151114084266
- Jennifer Fong, O.D.Sacramento, CA 958151295703023
- Corey Hoekstra, O.D.Sacramento, CA 958151659466035
- Benjamin Ja, O.D.Sacramento, CA 958151720172661
- Jeffrey Klink, O.D.Sacramento, CA 958151639174378
- Bill Lum, O.D.Sacramento, CA 958151184781882
Common questions
What is Karen Lynn Darkenwald, O.D.'s NPI number?
Karen Lynn Darkenwald, O.D.'s National Provider Identifier (NPI) is 1124177183, issued on Jan 9, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Karen Lynn Darkenwald, O.D. located?
The NPPES record lists a practice address at 1650 Response RD, Sacramento, CA, 95815. Phone: (916) 614-4015. Providers update this record themselves, so call before visiting.
How can I verify Karen Lynn Darkenwald, O.D.'s license?
NPPES lists California license number 8449T, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Karen Lynn Darkenwald, O.D. prescribe under Medicare Part D?
In 2024, Karen Lynn Darkenwald, O.D. had 73 Medicare Part D claims for 48 beneficiaries; the average among optometrist prescribers was 277. 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.