NPI registry status
Active
2026 NPPES data Nephrology Physician NPI 1891138616 M.D.
Verify on CMS → Ilka Decker, M.D.
Nephrology Physician in Ann Arbor, Michigan.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 10,569 in Nephrology Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
586
Medicare Part D claims · 88 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
88%
generic claims · 12% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Ilka Decker, M.D. filed 586 Medicare Part D claims in 2023 as a Nephrology Physician in Ann Arbor, Michigan, prescribing 88% generic.
- 586
- Part D claims, 2023
- 88%
- generic prescribing
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Ilka Decker, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
586 Top 34% higher than 66% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
✓
Board certification likely (heuristic, not verified)
Ilka Decker, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation - signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Ilka Decker, M.D.?
Quality data not reportedPrimary specialty
Nephrology Physician
Medicare Part D claims
586 60% vs specialty avg
Specialty distribution in Michigan
How Nephrology Physician compares to other specialties among Michigan providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Nephrology Physician. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Ilka Decker, M.D. appears in the CMS NPPES registry as a Nephrology Physician provider holding M.D. credentials at 1500 EAST MEDICAL CENTER DR, Ann Arbor, MI, 48109, with a listed phone of (734) 936-5548. NPI 1891138616 was issued on 04/11/2013.
Medicare Part D records for calendar year 2023 show 586 prescription claims written by this provider, covering 88 Medicare beneficiaries and totaling roughly $85K in drug spend, split 12% brand-name and 88% generic by claim count.
Nephrology Physician is a mid-sized specialty nationwide, with 10,569 enrolled providers across 55 states and an average of 1,454 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline.
Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist, always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1891138616 |
|---|---|
| Specialty | Nephrology Physician |
| Credentials | M.D. |
| Gender | Female |
| NPI Issued | 04/11/2013 |
Hospital and facility affiliations
Facilities where Ilka Decker, M.D. bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Regents OF The University OF Michigan
Ann Arbor, MI
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
License & disciplinary context - Michigan MI-BOM 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~41K Michigan medical licensees in 2023 - they are NOT specific to Ilka Decker, M.D.. To verify Ilka Decker, M.D.'s current license status, search the MI-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
123
Total board actions, Michigan 2023
Across 120 cases
3.00
Actions per 1,000 licensees
Michigan statewide rate
probation
Most common action type
44 cases
MI-BOM publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Michigan disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Ilka Decker, M.D. - brand share 12.0%
Nephrology Physician average
12% brand-name claims vs 88% generic, on 586 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
586
Total Claims
$85K
Total Drug Cost
88
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,457
- Total Day Supply
- 42,980
- Brand vs Generic
- 12% brand / 88% generic
- Brand Drug Cost
- $50K
- Generic Drug Cost
- $35K
- Antibiotic Claims
- 19
Patient Demographics
- Average Patient Age
- 68.7 years
- Avg HCC Risk Score
- 3.27
- Gender Split
- 56% female / 44% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Ilka Decker, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Amlodipine Besylate
Amlodipine Besylate
66 claims
- Losartan Potassium
Losartan Potassium
51 claims
- Potassium Citrate Er
Potassium Citrate Er
39 claims
- Allopurinol
Allopurinol
30 claims
- Lisinopril
Lisinopril
30 claims
- Bumetanide 25
Bumetanide
25 claims
- Doxazosin Mesylate 25
Doxazosin Mesylate
25 claims
- Potassium Chloride 25
Potassium Chloride
25 claims
| Drug | Claims |
|---|---|
| Amlodipine Besylate | 66 |
| Losartan Potassium | 51 |
| Potassium Citrate Er Potassium Citrate | 39 |
| Allopurinol | 30 |
| Lisinopril | 30 |
| Bumetanide | 25 |
| Doxazosin Mesylate | 25 |
| Potassium Chloride | 25 |
| Torsemide | 24 |
| Chlorthalidone | 21 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Nephrology Physician Overview
How Ilka Decker, M.D. fits within the Nephrology Physician landscape nationally.
10,569
Nephrology Physician Providers in US
55
States with Nephrology Physician
1,454
Avg Claims per Provider
Ilka Decker, M.D.'s 586 claims are below the specialty average of 1,454.
Nearby Nephrology Physician Providers in Michigan
Other clinicians with the same primary specialty enrolled in Michigan, drawn from the same CMS NPPES roster as Decker.
Mohamed Abdali
Detroit, MI
Dr. Mohamed Abdalla
M.D.
Flint, MI
Dr. Ameer Abdulrazzak
MD
Roseville, MI
Dr. Hassan Abou-Rass
M.D.
Detroit, MI
Dr. George Adam
M.D.
Battle Creek, MI
Compare Nephrology Physician nationally: see state-by-state distribution →
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Michigan medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Nephrology Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Ilka Decker, M.D.'s specialty? ▼
Ilka Decker, M.D. specializes in Nephrology Physician and practices in Ann Arbor, Michigan. Credentials: M.D..
How much does Ilka Decker, M.D. prescribe under Medicare Part D? ▼
In 2023, Ilka Decker, M.D. wrote 586 Medicare Part D claims totaling $85K in drug costs for 88 beneficiaries.
Where is Ilka Decker, M.D. located? ▼
Ilka Decker, M.D. is located at 1500 EAST MEDICAL CENTER DR, Ann Arbor, MI, 48109. Phone: (734) 936-5548.
What is Ilka Decker, M.D.'s NPI number? ▼
Ilka Decker, M.D.'s National Provider Identifier (NPI) is 1891138616, issued on 04/11/2013.
Does Ilka Decker, M.D. prescribe more brand-name or generic drugs? ▼
Ilka Decker, M.D.'s prescribing is 12% brand-name and 88% generic drugs by claim count, with $50K in brand drug costs.
How many Nephrology Physician providers are there in the US? ▼
There are 10,569 Nephrology Physician providers across 55 states in the US. The average Nephrology Physician provider writes 1,454 Medicare Part D claims per year.
What drugs does Ilka Decker, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Ilka Decker, M.D.'s most frequently prescribed drugs include Amlodipine Besylate, Losartan Potassium, Potassium Citrate Er. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Ilka Decker, M.D. accept Medicare? ▼
Ilka Decker, M.D. appears in CMS Medicare data with 586 Part D claims and 88 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Ilka Decker, M.D.'s credentials? ▼
Ilka Decker, M.D.'s NPI is 1891138616 with credentials M.D.. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Compiled from official public sources by the PlainDoctor editorial team.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.