2026 NPPES data Internal Medicine Physician NPI 1871554964 MD
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Ilia Shlimak, MD

Internal Medicine Physician in Acton, Massachusetts. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers — including 172,858 in Internal Medicine 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
3K
Medicare Part D claims · 401 beneficiaries · Internal Medicine Physician avg: 3K
MIPS score
87.1/100
▲ 4 pts above national avg 83.1 · Above neutral
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Ilia Shlimak, MD reported a CMS MIPS final score of 87.1/100 — above the 83.1 national average — and filed 3,450 Medicare Part D claims in 2023.

87.1/100
MIPS score · +4 vs avg
3K
Part D claims, 2023
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.

Ilia Shlimak, MD's MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

87 Top 46% higher than 54% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). Below this entry. 80–90: 129,887 scored providers (27%). This entry sits in this band. 90–100: 189,403 scored providers (40%). Above this entry. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

Where Ilia Shlimak, MD sits

This provider among internal medicine physician peers

Across the 36,260 internal medicine physician providers who report both Medicare Part D prescribing and a MIPS quality score, Ilia Shlimak, MD writes more Part D claims than 74% of them and scores higher on MIPS quality than 53% — placing this provider in the high-volume, high-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.

Part D claim volume vs MIPS quality, by specialty percentile

Lower volume · High qualityHigh volume · High qualityLower volume · Lower qualityHigh volume · Lower quality02550751000255075100Part D claim volume — percentile in specialtyMIPS quality — percentilePart D claim volume — percentile in specialty: 98 · MIPS quality — percentile: 88Part D claim volume — percentile in specialty: 43 · MIPS quality — percentile: 67Part D claim volume — percentile in specialty: 55 · MIPS quality — percentile: 18Part D claim volume — percentile in specialty: 82 · MIPS quality — percentile: 47Part D claim volume — percentile in specialty: 30 · MIPS quality — percentile: 42Part D claim volume — percentile in specialty: 77 · MIPS quality — percentile: 43Part D claim volume — percentile in specialty: 3 · MIPS quality — percentile: 85Part D claim volume — percentile in specialty: 42 · MIPS quality — percentile: 38Part D claim volume — percentile in specialty: 97 · MIPS quality — percentile: 52Part D claim volume — percentile in specialty: 65 · MIPS quality — percentile: 93Part D claim volume — percentile in specialty: 20 · MIPS quality — percentile: 97Part D claim volume — percentile in specialty: 37 · MIPS quality — percentile: 58Part D claim volume — percentile in specialty: 27 · MIPS quality — percentile: 25Part D claim volume — percentile in specialty: 28 · MIPS quality — percentile: 13Part D claim volume — percentile in specialty: 95 · MIPS quality — percentile: 0Part D claim volume — percentile in specialty: 93 · MIPS quality — percentile: 18Part D claim volume — percentile in specialty: 70 · MIPS quality — percentile: 92Part D claim volume — percentile in specialty: 15 · MIPS quality — percentile: 12Part D claim volume — percentile in specialty: 92 · MIPS quality — percentile: 18Part D claim volume — percentile in specialty: 0 · MIPS quality — percentile: 27Part D claim volume — percentile in specialty: 47 · MIPS quality — percentile: 30Part D claim volume — percentile in specialty: 67 · MIPS quality — percentile: 77Part D claim volume — percentile in specialty: 53 · MIPS quality — percentile: 97Part D claim volume — percentile in specialty: 73 · MIPS quality — percentile: 3Part D claim volume — percentile in specialty: 7 · MIPS quality — percentile: 50Part D claim volume — percentile in specialty: 23 · MIPS quality — percentile: 53Part D claim volume — percentile in specialty: 48 · MIPS quality — percentile: 10Part D claim volume — percentile in specialty: 52 · MIPS quality — percentile: 17Part D claim volume — percentile in specialty: 22 · MIPS quality — percentile: 33Part D claim volume — percentile in specialty: 78 · MIPS quality — percentile: 77Part D claim volume — percentile in specialty: 100 · MIPS quality — percentile: 2Part D claim volume — percentile in specialty: 85 · MIPS quality — percentile: 48Part D claim volume — percentile in specialty: 83 · MIPS quality — percentile: 73Part D claim volume — percentile in specialty: 35 · MIPS quality — percentile: 83Part D claim volume — percentile in specialty: 72 · MIPS quality — percentile: 32Part D claim volume — percentile in specialty: 12 · MIPS quality — percentile: 15Part D claim volume — percentile in specialty: 88 · MIPS quality — percentile: 40Part D claim volume — percentile in specialty: 25 · MIPS quality — percentile: 35Part D claim volume — percentile in specialty: 5 · MIPS quality — percentile: 60Part D claim volume — percentile in specialty: 57 · MIPS quality — percentile: 70Part D claim volume — percentile in specialty: 80 · MIPS quality — percentile: 5Part D claim volume — percentile in specialty: 62 · MIPS quality — percentile: 18Part D claim volume — percentile in specialty: 75 · MIPS quality — percentile: 57Part D claim volume — percentile in specialty: 87 · MIPS quality — percentile: 28Part D claim volume — percentile in specialty: 38 · MIPS quality — percentile: 88Part D claim volume — percentile in specialty: 8 · MIPS quality — percentile: 75Part D claim volume — percentile in specialty: 33 · MIPS quality — percentile: 87Part D claim volume — percentile in specialty: 63 · MIPS quality — percentile: 8Part D claim volume — percentile in specialty: 18 · MIPS quality — percentile: 72Part D claim volume — percentile in specialty: 68 · MIPS quality — percentile: 68Part D claim volume — percentile in specialty: 40 · MIPS quality — percentile: 45Part D claim volume — percentile in specialty: 50 · MIPS quality — percentile: 7Part D claim volume — percentile in specialty: 2 · MIPS quality — percentile: 62Part D claim volume — percentile in specialty: 60 · MIPS quality — percentile: 95Part D claim volume — percentile in specialty: 45 · MIPS quality — percentile: 37Part D claim volume — percentile in specialty: 10 · MIPS quality — percentile: 55Part D claim volume — percentile in specialty: 13 · MIPS quality — percentile: 82Part D claim volume — percentile in specialty: 32 · MIPS quality — percentile: 62Part D claim volume — percentile in specialty: 58 · MIPS quality — percentile: 97Part D claim volume — percentile in specialty: 17 · MIPS quality — percentile: 80Ilia Shlimak, MD — Part D claim volume — percentile in specialty: 74 · MIPS quality — percentile: 53
Part D claim volume vs MIPS quality, by specialty percentile

Each dot is one internal medicine physician peer from a representative sample of 60; the gold marker is Ilia Shlimak, MD. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.

Board certification likely (heuristic — not verified)

Ilia Shlimak, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting — 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 Ilia Shlimak, MD?

High performer (top quartile)

NPI registry status

Active

Issued 03/29/2006

NPI 1871554964

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

3,450 27% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

MIPS final score

87.1/100 4 pts vs avg

Above neutral band

vs 83.1 national avg

Specialty distribution in Massachusetts

How Internal Medicine Physician compares to other specialties among Massachusetts providers

Massachusetts providers

Largest specialties in Massachusetts (% of in-state providers)

Mental Health Counselor — 8.3%Mental Health Counselor8.3%Clinical Social Worker — 7.8%Clinical Social Worker7.8%Student in an Organized Health Care Education/Training Program — 6.2%Student in an Organized Health Care Education/Training Program6.2%Behavior Technician — 4.9%Behavior Technician4.9%Counselor — 4.3%Counselor4.3%Internal Medicine Physician — 3.7%Internal Medicine Physician3.7%
Largest specialties in Massachusetts (% of in-state providers)

Medicare quality performance — MIPS

Ilia Shlimak, MD's 2023 MIPS final score plotted against the Internal Medicine Physician national average

High performer (top quartile)
MIPS Final Score
87.1/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Internal Medicine Physician) — 87.1/100 vs national avg 83.1

0%100%National avg83%87.1%
MIPS final score (Internal Medicine Physician) — 87.1/100 vs national avg 83.1

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).

Ilia Shlimak, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 321 MAIN ST, Acton, MA, 01720, with a listed phone of (978) 635-8700. NPI 1871554964 was issued on 03/29/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Shlimak 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 3,450 prescription claims written by this provider, covering 401 Medicare beneficiaries and totaling roughly $200K in drug spend, with an opioid prescribing rate of 0.8%. 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 87.1/100 for the 2023 performance year (Quality 87, Cost 70.7), compared with the national average of 83.1.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 enrolled providers across 56 states and an average of 2,716 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

321 MAIN ST
Acton, MA 01720

Provider Details

NPI 1871554964
Specialty Internal Medicine Physician
Credentials MD
Gender Male
NPI Issued 03/29/2006

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

87.0554
Final Score
Avg: 83.1
86.9971
Quality
70.6876
Cost
99
Promoting Interoperability

Reporting: Group practice

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 Ilia Shlimak, MD. To verify Ilia Shlimak, 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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

3,450
Total Claims
$200K
Total Drug Cost
401
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
8,250
Total Day Supply
243,460
Generic Drug Cost
$79K
Opioid Claims
27 (0.8% rate)
Antibiotic Claims
60

Patient Demographics

Average Patient Age
74.5 years
Avg HCC Risk Score
0.98
Gender Split
28% female / 72% male
Age Distribution
<65: 13, 65-74: 199, 75-84: 146, 85+: 43

Top Prescribed Drugs (Medicare Part D)

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

What Ilia Shlimak, 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
Atorvastatin Calcium
406
Losartan Potassium
304
Rosuvastatin Calcium
189
Amlodipine Besylate
145
Metoprolol Succinate
132
Irbesartan
127
Lisinopril
119
Hydrochlorothiazide
112
Chlorthalidone
82
Omeprazole
76

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

Internal Medicine Physician Overview

How Ilia Shlimak, MD fits within the Internal Medicine Physician landscape nationally.

172,858
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider

Ilia Shlimak, MD's 3,450 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Massachusetts

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

Compare Internal Medicine 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 Massachusetts medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Internal Medicine 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.

Frequently Asked Questions

What is Ilia Shlimak, MD's specialty?
Ilia Shlimak, MD specializes in Internal Medicine Physician and practices in Acton, Massachusetts. Credentials: MD.
How much does Ilia Shlimak, MD prescribe under Medicare Part D?
In 2023, Ilia Shlimak, MD wrote 3,450 Medicare Part D claims totaling $200K in drug costs for 401 beneficiaries.
What is Ilia Shlimak, MD's Medicare quality score?
Ilia Shlimak, MD has a CMS MIPS Final Score of 87.1/100 (Quality: 87, Cost: 70.7). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Ilia Shlimak, MD located?
Ilia Shlimak, MD is located at 321 MAIN ST, Acton, MA, 01720. Phone: (978) 635-8700.
What is Ilia Shlimak, MD's NPI number?
Ilia Shlimak, MD's National Provider Identifier (NPI) is 1871554964, issued on 03/29/2006.
Does Ilia Shlimak, MD prescribe opioids?
Yes, Ilia Shlimak, MD had 27 opioid claims in 2023 with an opioid prescribing rate of 0.8%.
How many Internal Medicine Physician providers are there in the US?
There are 172,858 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Ilia Shlimak, MD prescribe most often?
Based on 2023 Medicare Part D data, Ilia Shlimak, MD's most frequently prescribed drugs include Atorvastatin Calcium, Losartan Potassium, Rosuvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Ilia Shlimak, MD accept Medicare?
Ilia Shlimak, MD appears in CMS Medicare data with 3,450 Part D claims and 401 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Ilia Shlimak, MD's credentials?
Ilia Shlimak, MD's NPI is 1871554964 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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.