2026 NPPES data Infectious Disease Physician NPI 1558579045 M.D.
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Matthew Grant, M.D.

Infectious Disease Physician in New Haven, Connecticut. This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 8,292 in Infectious Disease 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
123
Medicare Part D claims · 30 beneficiaries · Infectious Disease Physician avg: 816
Generic prescribing
83%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
73.6/100
▼ 10 pts below national avg 83.1 · Mid-tier
Compiled from official public sources by the PlainDoctor editorial team.

What the federal data shows

Matthew Grant, M.D. reported a CMS MIPS final score of 73.6/100 - below the 83.1 national average - and filed 123 Medicare Part D claims in 2023.

73.6/100
MIPS score · -10 vs avg
123
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.

Matthew Grant, M.D.'s MIPS score vs every scored U.S. clinician

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

74 11th percentile higher than 11% 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%). This entry sits in this band. 80–90: 129,887 scored providers (27%). Above this entry. 90+: 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 Matthew Grant, M.D. sits

This provider among infectious disease physician peers

Across the 2,276 infectious disease physician providers who report both Medicare Part D prescribing and a MIPS quality score, Matthew Grant, M.D. writes more Part D claims than 21% of them and scores higher on MIPS quality than 12% - placing this provider in the lower-volume, lower-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 quality0255075100023.647.370.994.5Part D claim volume, percentile in specialtyMIPS quality, percentilePart D claim volume, percentile in specialty: 85 · MIPS quality, percentile: 88Part D claim volume, percentile in specialty: 28 · MIPS quality, percentile: 75Part D claim volume, percentile in specialty: 65 · MIPS quality, percentile: 73Part D claim volume, percentile in specialty: 95 · MIPS quality, percentile: 55Part D claim volume, percentile in specialty: 63 · MIPS quality, percentile: 43Part D claim volume, percentile in specialty: 7 · MIPS quality, percentile: 82Part D claim volume, percentile in specialty: 68 · MIPS quality, percentile: 42Part D claim volume, percentile in specialty: 82 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 47 · MIPS quality, percentile: 65Part D claim volume, percentile in specialty: 48 · MIPS quality, percentile: 87Part D claim volume, percentile in specialty: 10 · MIPS quality, percentile: 48Part D claim volume, percentile in specialty: 27 · MIPS quality, percentile: 57Part D claim volume, percentile in specialty: 25 · MIPS quality, percentile: 82Part D claim volume, percentile in specialty: 30 · MIPS quality, percentile: 68Part D claim volume, percentile in specialty: 45 · MIPS quality, percentile: 80Part D claim volume, percentile in specialty: 52 · MIPS quality, percentile: 33Part D claim volume, percentile in specialty: 50 · MIPS quality, percentile: 32Part D claim volume, percentile in specialty: 70 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 32 · MIPS quality, percentile: 12Part D claim volume, percentile in specialty: 35 · MIPS quality, percentile: 70Part D claim volume, percentile in specialty: 53 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 0 · MIPS quality, percentile: 78Part D claim volume, percentile in specialty: 57 · MIPS quality, percentile: 60Part D claim volume, percentile in specialty: 37 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 15 · MIPS quality, percentile: 2Part D claim volume, percentile in specialty: 72 · MIPS quality, percentile: 10Part D claim volume, percentile in specialty: 90 · MIPS quality, percentile: 28Part D claim volume, percentile in specialty: 20 · MIPS quality, percentile: 82Part D claim volume, percentile in specialty: 22 · MIPS quality, percentile: 37Part D claim volume, percentile in specialty: 40 · MIPS quality, percentile: 65Part D claim volume, percentile in specialty: 5 · MIPS quality, percentile: 25Part D claim volume, percentile in specialty: 43 · MIPS quality, percentile: 57Part D claim volume, percentile in specialty: 72 · MIPS quality, percentile: 62Part D claim volume, percentile in specialty: 88 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 0 · MIPS quality, percentile: 77Part D claim volume, percentile in specialty: 18 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 3 · MIPS quality, percentile: 30Part D claim volume, percentile in specialty: 23 · MIPS quality, percentile: 38Part D claim volume, percentile in specialty: 38 · MIPS quality, percentile: 50Part D claim volume, percentile in specialty: 58 · MIPS quality, percentile: 8Part D claim volume, percentile in specialty: 97 · MIPS quality, percentile: 53Part D claim volume, percentile in specialty: 75 · MIPS quality, percentile: 17Part D claim volume, percentile in specialty: 92 · MIPS quality, percentile: 5Part D claim volume, percentile in specialty: 60 · MIPS quality, percentile: 50Part D claim volume, percentile in specialty: 87 · MIPS quality, percentile: 3Part D claim volume, percentile in specialty: 62 · MIPS quality, percentile: 27Part D claim volume, percentile in specialty: 13 · MIPS quality, percentile: 35Part D claim volume, percentile in specialty: 83 · MIPS quality, percentile: 7Part D claim volume, percentile in specialty: 98 · MIPS quality, percentile: 90Part D claim volume, percentile in specialty: 12 · MIPS quality, percentile: 47Part D claim volume, percentile in specialty: 67 · MIPS quality, percentile: 63Part D claim volume, percentile in specialty: 80 · MIPS quality, percentile: 40Part D claim volume, percentile in specialty: 33 · MIPS quality, percentile: 22Part D claim volume, percentile in specialty: 78 · MIPS quality, percentile: 70Part D claim volume, percentile in specialty: 55 · MIPS quality, percentile: 0Part D claim volume, percentile in specialty: 42 · MIPS quality, percentile: 17Part D claim volume, percentile in specialty: 8 · MIPS quality, percentile: 23Part D claim volume, percentile in specialty: 93 · MIPS quality, percentile: 43Part D claim volume, percentile in specialty: 100 · MIPS quality, percentile: 17Part D claim volume, percentile in specialty: 77 · MIPS quality, percentile: 15Matthew Grant, M.D.-Part D claim volume, percentile in specialty: 21 · MIPS quality, percentile: 12
Part D claim volume vs MIPS quality, by specialty percentile

Each dot is one infectious disease physician peer from a representative sample of 60; the gold marker is Matthew Grant, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.

Board certification likely (heuristic, not verified)

Matthew Grant, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + MIPS quality reporting + 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 Matthew Grant, M.D.?

Below national average

NPI registry status

Active

Issued 05/18/2007

NPI 1558579045

Primary specialty

Infectious Disease Physician

Mid-sized

8,292 US NPIs in this specialty

Medicare Part D claims

123 85% vs specialty avg

2023 prescription claims

Specialty avg: 816

MIPS final score

73.6/100 9.5 pts vs avg

Mid-tier band

vs 83.1 national avg

Specialty distribution in Connecticut

How Infectious Disease Physician compares to other specialties among Connecticut providers

Connecticut providers
Clinical Social Worker - 8.4%Clinical Social Worker8.4%Student in an Organized Health Care Education/Training Program - 7.7%Student in an Organized Health Care Education/Training Program7.7%Physical Therapist - 4.2%Physical Therapist4.2%Pharmacist - 3.9%Pharmacist3.9%Internal Medicine Physician - 3.4%Internal Medicine Physician3.4%Mental Health Counselor - 3.2%Mental Health Counselor3.2%Infectious Disease Physician - 0.2%Infectious Disease Physician0.2%
Largest specialties in Connecticut (% of in-state providers)

Medicare quality performance, MIPS

Matthew Grant, M.D.'s 2023 MIPS final score plotted against the Infectious Disease Physician national average

Below national average
MIPS Final Score
73.6/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Infectious Disease Physician) - 73.6/100 vs national avg 83.1

0%100%National avg83%73.6%
MIPS final score (Infectious Disease Physician) - 73.6/100 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).

Matthew Grant, M.D. appears in the CMS NPPES registry as a Infectious Disease Physician provider holding M.D. credentials at 800 HOWARD AVE, New Haven, CT, 06519, with a listed phone of (203) 785-3561. NPI 1558579045 was issued on 05/18/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Grant 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 123 prescription claims written by this provider, covering 30 Medicare beneficiaries and totaling roughly $163K in drug spend, split 17% brand-name and 83% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 73.6/100 for the 2023 performance year (Quality 75.8, Cost 51.4), compared with the national average of 83.1.

Infectious Disease Physician is a mid-sized specialty nationwide, with 8,292 enrolled providers across 54 states and an average of 816 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

800 HOWARD AVE
New Haven, CT 06519

Provider Details

NPI 1558579045
Specialty Infectious Disease Physician
Credentials M.D.
Gender Male
NPI Issued 05/18/2007

CMS Quality Score (MIPS)

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

73.5637
Final Score
Avg: 83.1
75.8435
Quality
51.4318
Cost
74
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where Matthew Grant, 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.

Yale University
New Haven, CT

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

Matthew Grant, M.D. - brand share 17.0%
Infectious Disease Physician average

17% brand-name claims vs 83% generic, on 123 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.

123
Total Claims
$163K
Total Drug Cost
30
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
234
Total Day Supply
6,617
Brand vs Generic
17% brand / 83% generic
Brand Drug Cost
$145K
Generic Drug Cost
$18K
Antibiotic Claims
86

Patient Demographics

Average Patient Age
71.0 years
Avg HCC Risk Score
2.70
Gender Split
47% female / 53% male

Top Prescribed Drugs (Medicare Part D)

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

What Matthew Grant, 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
Cephalexin
42
Cresemba
Isavuconazonium Sulfate
15
Doxycycline Monohydrate
15
Voriconazole
13

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

Infectious Disease Physician Overview

How Matthew Grant, M.D. fits within the Infectious Disease Physician landscape nationally.

8,292
Infectious Disease Physician Providers in US
54
States with Infectious Disease Physician
816
Avg Claims per Provider

Matthew Grant, M.D.'s 123 claims are below the specialty average of 816.

Nearby Infectious Disease Physician Providers in Connecticut

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

Compare Infectious Disease 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 Connecticut medical board, federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Infectious Disease 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 Matthew Grant, M.D.'s specialty?
Matthew Grant, M.D. specializes in Infectious Disease Physician and practices in New Haven, Connecticut. Credentials: M.D..
How much does Matthew Grant, M.D. prescribe under Medicare Part D?
In 2023, Matthew Grant, M.D. wrote 123 Medicare Part D claims totaling $163K in drug costs for 30 beneficiaries.
What is Matthew Grant, M.D.'s Medicare quality score?
Matthew Grant, M.D. has a CMS MIPS Final Score of 73.6/100 (Quality: 75.8, Cost: 51.4). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Matthew Grant, M.D. located?
Matthew Grant, M.D. is located at 800 HOWARD AVE, New Haven, CT, 06519. Phone: (203) 785-3561.
What is Matthew Grant, M.D.'s NPI number?
Matthew Grant, M.D.'s National Provider Identifier (NPI) is 1558579045, issued on 05/18/2007.
Does Matthew Grant, M.D. prescribe more brand-name or generic drugs?
Matthew Grant, M.D.'s prescribing is 17% brand-name and 83% generic drugs by claim count, with $145K in brand drug costs.
How many Infectious Disease Physician providers are there in the US?
There are 8,292 Infectious Disease Physician providers across 54 states in the US. The average Infectious Disease Physician provider writes 816 Medicare Part D claims per year.
What drugs does Matthew Grant, M.D. prescribe most often?
Based on 2023 Medicare Part D data, Matthew Grant, M.D.'s most frequently prescribed drugs include Cephalexin, Cresemba, Doxycycline Monohydrate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Matthew Grant, M.D. accept Medicare?
Matthew Grant, M.D. appears in CMS Medicare data with 123 Part D claims and 30 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Matthew Grant, M.D.'s credentials?
Matthew Grant, M.D.'s NPI is 1558579045 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.
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.