2026 NPPES data Nephrology Physician NPI 1558343129 MD
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SEBASTIAN SEPULVEDA, MD

Nephrology Physician in CHELMSFORD, Massachusetts. 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
6K
Medicare Part D claims · 613 beneficiaries · Nephrology Physician avg: 1K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

SEBASTIAN SEPULVEDA, MD filed 5,661 Medicare Part D claims in 2023 as a Nephrology Physician in CHELMSFORD, Massachusetts, prescribing 89% generic.

6K
Part D claims, 2023
89%
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.

SEBASTIAN SEPULVEDA, MD's Medicare Part D volume vs every U.S. prescriber

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

5,661 Top 5% higher than 95% 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)

SEBASTIAN SEPULVEDA, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 2 hospital affiliations — 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 SEBASTIAN SEPULVEDA, MD?

Quality data not reported

NPI registry status

Active

Issued 11/18/2005

NPI 1558343129

Primary specialty

Nephrology Physician

Mid-sized

10,534 US NPIs in this specialty

Medicare Part D claims

5,661 289% vs specialty avg

2023 prescription claims

Specialty avg: 1,454

Specialty distribution in Massachusetts

How Nephrology Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Nephrology Physician share within Massachusetts

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

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).

SEBASTIAN SEPULVEDA, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 9 NORTH RD, CHELMSFORD, MA, 01824, with a listed phone of (978) 458-2005. NPI 1558343129 was issued on 11/18/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what SEPULVEDA 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 5,661 prescription claims written by this provider, covering 613 Medicare beneficiaries and totaling roughly $761K in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 0.7%. 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

9 NORTH RD
CHELMSFORD, MA 01824

Provider Details

NPI 1558343129
Specialty Nephrology Physician
Credentials MD
Gender Male
NPI Issued 11/18/2005

Hospital and facility affiliations

Facilities where SEBASTIAN SEPULVEDA, MD 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.

COMMONWEALTH MEDICAL PRACTICE LLC
CHELMSFORD, MA
LOWELL GENERAL INPATIENT SPECIALISTS PLLC
LOWELL, MA

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 — Massachusetts BORIM 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 ~38K Massachusetts medical licensees in 2023 — they are NOT specific to SEBASTIAN SEPULVEDA, MD. To verify SEBASTIAN SEPULVEDA, MD's current license status, search the BORIM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.

80
Total board actions, Massachusetts 2023
Across 78 cases
2.11
Actions per 1,000 licensees
Massachusetts statewide rate
probation
Most common action type
29 cases

BORIM 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 Massachusetts disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.

Brand vs generic prescribing mix · Typical

SEBASTIAN SEPULVEDA, MD — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 5,661 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.

5,661
Total Claims
$761K
Total Drug Cost
613
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
11,713
Total Day Supply
341,697
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$583K
Generic Drug Cost
$176K
Opioid Claims
38 (0.7% rate)
Antibiotic Claims
124

Patient Demographics

Average Patient Age
73.7 years
Avg HCC Risk Score
2.28
Gender Split
54% female / 46% male
Age Distribution
<65: 87, 65-74: 240, 75-84: 191, 85+: 95

Top Prescribed Drugs (Medicare Part D)

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

What SEBASTIAN SEPULVEDA, MD 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
Amlodipine Besylate
408
Atorvastatin Calcium
377
Calcitriol
358
Metoprolol Succinate
336
Lisinopril
291
Furosemide
242
Losartan Potassium
235
Hydrochlorothiazide
211
Omeprazole
153
Pantoprazole Sodium
111

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

Nephrology Physician Overview

How SEBASTIAN SEPULVEDA, MD 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

SEBASTIAN SEPULVEDA, MD's 5,661 claims are above the specialty average of 1,454.

Nearby Nephrology Physician Providers in Massachusetts

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

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

Frequently Asked Questions

What is SEBASTIAN SEPULVEDA, MD's specialty?
SEBASTIAN SEPULVEDA, MD specializes in Nephrology Physician and practices in CHELMSFORD, Massachusetts. Credentials: MD.
How much does SEBASTIAN SEPULVEDA, MD prescribe under Medicare Part D?
In 2023, SEBASTIAN SEPULVEDA, MD wrote 5,661 Medicare Part D claims totaling $761K in drug costs for 613 beneficiaries.
Where is SEBASTIAN SEPULVEDA, MD located?
SEBASTIAN SEPULVEDA, MD is located at 9 NORTH RD, CHELMSFORD, MA, 01824. Phone: (978) 458-2005.
What is SEBASTIAN SEPULVEDA, MD's NPI number?
SEBASTIAN SEPULVEDA, MD's National Provider Identifier (NPI) is 1558343129, issued on 11/18/2005.
Does SEBASTIAN SEPULVEDA, MD prescribe more brand-name or generic drugs?
SEBASTIAN SEPULVEDA, MD's prescribing is 11% brand-name and 89% generic drugs by claim count, with $583K in brand drug costs.
Does SEBASTIAN SEPULVEDA, MD prescribe opioids?
Yes, SEBASTIAN SEPULVEDA, MD had 38 opioid claims in 2023 with an opioid prescribing rate of 0.7%.
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 SEBASTIAN SEPULVEDA, MD prescribe most often?
Based on 2023 Medicare Part D data, SEBASTIAN SEPULVEDA, MD's most frequently prescribed drugs include Amlodipine Besylate, Atorvastatin Calcium, Calcitriol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does SEBASTIAN SEPULVEDA, MD accept Medicare?
SEBASTIAN SEPULVEDA, MD appears in CMS Medicare data with 5,661 Part D claims and 613 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify SEBASTIAN SEPULVEDA, MD's credentials?
SEBASTIAN SEPULVEDA, MD's NPI is 1558343129 with credentials MD. 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