2026 NPPES data Nephrology Physician NPI 1891138616 M.D.
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ILKA DECKER, M.D.

Nephrology Physician in ANN ARBOR, Michigan. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
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
What the federal data reveals: ILKA DECKER, M.D. is a Nephrology Physician ([object Object]) practicing in ANN ARBOR, Michigan with a Medicare Part D prescribing footprint of 586 claims across 88 beneficiaries — 12% brand-name prescribing .

What stands out: ILKA DECKER, M.D. filed 586 Medicare Part D claims in 2023 across ANN ARBOR, Michigan. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

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).

ILKA DECKER, M.D. at a glance

Quality data not reported

NPI registry status

Active

Issued 04/11/2013

NPI 1891138616

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

586 60% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

Specialty distribution in Michigan

How Nephrology Physician compares to other specialties among Michigan providers

Michigan providers

Nephrology Physician share within Michigan

1. Nephrology Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Nephrology Physician share within Michigan

Specialty board-certification context

Estimated specialty board-certified rate — Nephrology Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Nephrology Physician ABMS/AOA estimate

Est. board-certified rate (Nephrology Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Nephrology Physician) — ABMS / AOA estimate

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. is a Nephrology Physician provider practicing in ANN ARBOR, Michigan, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: M.D.. NPI: 1891138616. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

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. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DECKER most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

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. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Nephrology Physician is a mid-sized specialty nationwide, with 10,534 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

1500 EAST MEDICAL CENTER DR
ANN ARBOR, MI 48109

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%
Specialty average (est.)

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.

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.

10,534
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.

Compare Nephrology Physician nationally: see state-by-state distribution →

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 10,534 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

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