NPI registry status
Active
2026 NPPES data Critical Care Medicine (Internal Medicine) Physician NPI 1225666357 DO
Verify on CMS → Grant Hallock, DO
Critical Care Medicine (Internal Medicine) Physician in Park Ridge, Illinois.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 6,916 in Critical Care Medicine (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
29
Medicare Part D claims · Critical Care Medicine (Internal Medicine) Physician avg: 1K
What the federal data shows
Grant Hallock, DO filed 29 Medicare Part D claims in 2024 as a Critical Care Medicine (Internal Medicine) Physician in Park Ridge, Illinois.
- 29
- Part D claims, 2024
- Likely
- board-certified (heuristic)
- ≥0th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Grant Hallock, DO
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1225666357), first enumerated 04/01/2020.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 29 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- State context
State board disciplinary context
Illinois statewide board action statistics are published annually — these figures describe aggregate state activity, not Grant Hallock, DO's individual license status. Verify directly with the state medical board.
Source: IDFPR annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1225666357 · Critical Care Medicine (Internal Medicine) Physician
NPI-10 · ENUM-RECENT · TAX-MID · RX-TRACE · BOOK-THIN · PHOTO-ENUM
- NPI-10 1225666357
- ENUM-RECENT 2020
- TAX-MID 7K Critical Care
- RX-TRACE 29
- BOOK-THIN 303 in Illinois
- PHOTO-ENUM Bo Qin, MD · 2020
Grant Hallock, DO's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
29 ≥ 0th percentile 0% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
Grant Hallock, DO 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 Grant Hallock, DO?
Quality data not reportedPrimary specialty
Critical Care Medicine (Internal Medicine) Physician
Medicare Part D claims
29 97% vs specialty avg
Specialty distribution in Illinois
How Critical Care Medicine (Internal Medicine) Physician compares to other specialties among Illinois providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Critical Care Medicine (Internal Medicine) Physician. Verify directly:
How MIPS and board certification work
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).
Practice Address
Provider Details
| NPI | 1225666357 |
|---|---|
| Specialty | Critical Care Medicine (Internal Medicine) Physician |
| Credentials | DO |
| Gender | Male |
| NPI Issued | 04/01/2020 |
Hospital and facility affiliations
Facilities where Grant Hallock, DO 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.
Incare LLC
Nashua, NH
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 - Illinois IDFPR 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 ~42K Illinois medical licensees in 2023 - they are NOT specific to Grant Hallock, DO. To verify Grant Hallock, DO's current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases
IDFPR 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 Illinois 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 2024.
29
Total Claims
$854
Total Drug Cost
N/A
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 31
- Total Day Supply
- 887
- Generic Drug Cost
- $414
Patient Demographics
- Average Patient Age
- 74.2 years
- Avg HCC Risk Score
- 1.39
More Critical Care Medicine (Internal Medicine) Physician in IL →
All providers in Illinois →
Compare specialties →
Critical Care Medicine (Internal Medicine) Physician Overview
How Grant Hallock, DO fits within the Critical Care Medicine (Internal Medicine) Physician landscape nationally.
6,916
Critical Care Medicine (Internal Medicine) Physician Providers in US
53
States with Critical Care Medicine (Internal Medicine) Physician
1,103
Avg Claims per Provider
Grant Hallock, DO's 29 claims are below the specialty average of 1,103.
Nationwide Critical Care Medicine (Internal Medicine) Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Hallock, both outside Illinois so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2020)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Critical Care Medicine (Internal Medicine) Physician Providers in Illinois
Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as Hallock.
One of 303 Critical Care Medicine (Internal Medicine) Physician providers enrolled in Illinois, 5 are shown here.
Frequently Asked Questions
What is Grant Hallock, DO's specialty? ▼
Grant Hallock, DO specializes in Critical Care Medicine (Internal Medicine) Physician and practices in Park Ridge, Illinois. Credentials: DO.
How much does Grant Hallock, DO prescribe under Medicare Part D? ▼
In 2024, Grant Hallock, DO wrote 29 Medicare Part D claims totaling $854 in drug costs for N/A beneficiaries.
Where is Grant Hallock, DO located? ▼
Grant Hallock, DO is located at 1775 DEMPSTER ST, Park Ridge, IL, 60068. Phone: (847) 723-2210.
What is Grant Hallock, DO's NPI number? ▼
Grant Hallock, DO's National Provider Identifier (NPI) is 1225666357, issued on 04/01/2020.
How many Critical Care Medicine (Internal Medicine) Physician providers are there in the US? ▼
There are 6,916 Critical Care Medicine (Internal Medicine) Physician providers across 53 states in the US. The average Critical Care Medicine (Internal Medicine) Physician provider writes 1,103 Medicare Part D claims per year.
Does Grant Hallock, DO accept Medicare? ▼
Grant Hallock, DO appears in CMS Medicare data with 29 Part D claims and N/A Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Grant Hallock, DO's credentials? ▼
Grant Hallock, DO's NPI is 1225666357 with credentials DO. 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
View source datasets and methodology notes
- 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 (2024). 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 August 2026 (NPPES) / 2024 (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
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.