2026 NPPES data Rheumatology Physician NPI 1558555896 M.D.
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MARTY MERTENS, M.D.

Rheumatology Physician in WOODBURY, Minnesota. 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
3K
Medicare Part D claims · 457 beneficiaries · Rheumatology Physician avg: 2K
Generic prescribing
83%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

MARTY MERTENS, M.D. filed 2,611 Medicare Part D claims in 2023 as a Rheumatology Physician in WOODBURY, Minnesota, prescribing 83% generic.

3K
Part D claims, 2023
83%
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.

MARTY MERTENS, M.D.'s Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

2,611 Top 13% higher than 87% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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)

MARTY MERTENS, 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 MARTY MERTENS, M.D.?

Quality data not reported

NPI registry status

Active

Issued 08/29/2007

NPI 1558555896

Primary specialty

Rheumatology Physician

Mid-sized

6,181 US NPIs in this specialty

Medicare Part D claims

2,611 27% vs specialty avg

2023 prescription claims

Specialty avg: 2,054

Specialty distribution in Minnesota

How Rheumatology Physician compares to other specialties among Minnesota providers

Minnesota providers

Rheumatology Physician share within Minnesota

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Rheumatology 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).

MARTY MERTENS, M.D. appears in the CMS NPPES registry as a Rheumatology Physician provider holding M.D. credentials at 4040 RADIO DR, WOODBURY, MN, 55129, with a listed phone of (651) 439-8807. NPI 1558555896 was issued on 08/29/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MERTENS 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 2,611 prescription claims written by this provider, covering 457 Medicare beneficiaries and totaling roughly $2.3 million in drug spend, split 17% brand-name and 83% generic by claim count, with an opioid prescribing rate of 1.6%. 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.

Rheumatology Physician is a mid-sized specialty nationwide, with 6,181 enrolled providers across 52 states and an average of 2,054 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

4040 RADIO DR
WOODBURY, MN 55129

Provider Details

NPI 1558555896
Specialty Rheumatology Physician
Credentials M.D.
Gender Male
NPI Issued 08/29/2007

Hospital and facility affiliations

Facilities where MARTY MERTENS, 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.

INFINITE HEALTH COLLABORATIVE, PA
HUDSON, WI

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Brand vs generic prescribing mix · Typical

MARTY MERTENS, M.D. — brand share 17.0%
Specialty average (est.)

17% brand-name claims vs 83% generic, on 2,611 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.

2,611
Total Claims
$2.3M
Total Drug Cost
457
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
5,738
Total Day Supply
168,219
Brand vs Generic
17% brand / 83% generic
Brand Drug Cost
$2.1M
Generic Drug Cost
$131K
Opioid Claims
41 (1.6% rate)

Patient Demographics

Average Patient Age
73.1 years
Avg HCC Risk Score
1.38
Gender Split
65% female / 35% male
Age Distribution
<65: 42, 65-74: 211, 75-84: 166, 85+: 38

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What MARTY MERTENS, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Methotrexate
Methotrexate Sodium
476
Hydroxychloroquine Sulfate
396
Prednisone
370
Leflunomide
126
Celecoxib
98
Enbrel Sureclick
Etanercept
97
Sulfasalazine
93
Leucovorin Calcium
82
Allopurinol
78
Meloxicam
67

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Rheumatology Physician Overview

How MARTY MERTENS, M.D. fits within the Rheumatology Physician landscape nationally.

6,181
Rheumatology Physician Providers in US
52
States with Rheumatology Physician
2,054
Avg Claims per Provider

MARTY MERTENS, M.D.'s 2,611 claims are above the specialty average of 2,054.

Nearby Rheumatology Physician Providers in Minnesota

Other clinicians with the same primary specialty enrolled in Minnesota, drawn from the same CMS NPPES roster as MERTENS.

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

Frequently Asked Questions

What is MARTY MERTENS, M.D.'s specialty?
MARTY MERTENS, M.D. specializes in Rheumatology Physician and practices in WOODBURY, Minnesota. Credentials: M.D..
How much does MARTY MERTENS, M.D. prescribe under Medicare Part D?
In 2023, MARTY MERTENS, M.D. wrote 2,611 Medicare Part D claims totaling $2.3M in drug costs for 457 beneficiaries.
Where is MARTY MERTENS, M.D. located?
MARTY MERTENS, M.D. is located at 4040 RADIO DR, WOODBURY, MN, 55129. Phone: (651) 439-8807.
What is MARTY MERTENS, M.D.'s NPI number?
MARTY MERTENS, M.D.'s National Provider Identifier (NPI) is 1558555896, issued on 08/29/2007.
Does MARTY MERTENS, M.D. prescribe more brand-name or generic drugs?
MARTY MERTENS, M.D.'s prescribing is 17% brand-name and 83% generic drugs by claim count, with $2.1M in brand drug costs.
Does MARTY MERTENS, M.D. prescribe opioids?
Yes, MARTY MERTENS, M.D. had 41 opioid claims in 2023 with an opioid prescribing rate of 1.6%.
How many Rheumatology Physician providers are there in the US?
There are 6,181 Rheumatology Physician providers across 52 states in the US. The average Rheumatology Physician provider writes 2,054 Medicare Part D claims per year.
What drugs does MARTY MERTENS, M.D. prescribe most often?
Based on 2023 Medicare Part D data, MARTY MERTENS, M.D.'s most frequently prescribed drugs include Methotrexate, Hydroxychloroquine Sulfate, Prednisone. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MARTY MERTENS, M.D. accept Medicare?
MARTY MERTENS, M.D. appears in CMS Medicare data with 2,611 Part D claims and 457 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MARTY MERTENS, M.D.'s credentials?
MARTY MERTENS, M.D.'s NPI is 1558555896 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