Doctor profile · Federal record

Dr. Derek Illastron, MD

Internal Medicine Physician (CMS: Hospitalist) · Internal Medicine Physician · Kahului, HI

  • NPI 1790949956
  • Accepts Medicare
  • MIPS 87.0 / 100 · 2023
  • 21 yrs in practice
  • Licensed in 2 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
110 E Kaahumanu Ave
Kahului, HI 967322118
(808) 242-6464
fax (808) 243-2367
Mailing address
2180 Main St
Wailuku, HI 967931625

Credentials & registration

NPPES · NUCC
NPI registered
July 2008 — 18 yrs on file
Profile last updated
March 19, 2019
Year of graduation
2005 — 21 yrs since
Specialty taxonomy
207R00000X — NUCC code
State licenses (2)
Hawaii #MD-18353 · Massachusetts #235414

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1790949956. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
443
Distinct HCPCS
3
Medicare allowed
$52,841
HCPCS Description Services Patients Avg allowed
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 373 92 $118
99239 Hospital discharge day management, more than 30 minutes 55 54 $113
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 15 15 $175

In context: peer comparison

Among 3 peers in this city , average services per provider: 117. This provider delivers 3.8× the peer median.

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
222
Patients
42
Total drug cost
$21,617
Drug Type Claims Patients Total cost
Azathioprine Generic 23 0 $927
Atorvastatin Calcium Generic 20 15 $402
Eliquis (Apixaban) Brand 19 0 $10,575
Amoxicillin-Clavulanate Potass (Amoxicillin/Potassium Clav) Brand 16 16 $209
Gabapentin Generic 15 0 $109
Lisinopril Generic 15 0 $92
Advair Diskus (Fluticasone Propion/Salmeterol) Brand 14 0 $5,731
Famotidine Generic 14 0 $188
Levothyroxine Sodium Generic 14 0 $168
Methotrexate (Methotrexate Sodium) Brand 14 0 $265

Frequently asked questions

Auto-generated from federal data
What is Dr. Derek Illastron's medical specialty?
Dr. Derek Illastron practices Internal Medicine Physician in Kahului, HI.
Where does Dr. Derek Illastron practice?
Dr. Derek Illastron practices at 110 E Kaahumanu Ave, Kahului, HI 967322118. Office phone: 8082426464.
What is Dr. Derek Illastron's NPI?
Dr. Derek Illastron's National Provider Identifier (NPI) is 1790949956, issued by NPPES.
Does Dr. Derek Illastron accept Medicare assignment?
Yes. Dr. Derek Illastron accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Derek Illastron commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Hospital discharge day management (HCPCS 99239); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.