Doctor profile · Federal record

Dr. Helen Chang, MD

Internal Medicine Physician · Mission Viejo, CA

  • NPI 1639134687
  • 20 yrs on file
  • Female
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
25982 Pala, Suite 250
Mission Viejo, CA 926916719
(949) 588-0051
fax (949) 588-0052

Credentials & registration

NPPES · NUCC
NPI registered
April 2006 — 20 yrs on file
Profile last updated
July 8, 2007
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A65088

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1639134687. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
65
Distinct HCPCS
3
Medicare allowed
$8,082
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 30 25 $139
99213 Established patient office or other outpatient visit, 20-29 minutes 24 21 $99
G0439 Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit 11 11 $140

In context: peer comparison

Among 22 peers in this city , average services per provider: 176. This provider delivers 0.4× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$146
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Amgen Inc. 1 $146.24

By nature of payment

Food and Beverage
$146

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
735
Patients
155
Total drug cost
$11,665
Drug Type Claims Patients Total cost
Atorvastatin Calcium Generic 113 36 $1,526
Amlodipine Besylate Generic 92 26 $818
Levothyroxine Sodium Generic 72 18 $1,587
Losartan Potassium Generic 67 18 $1,071
Lisinopril Generic 49 14 $394
Zolpidem Tartrate Generic 49 0 $158
Omeprazole Generic 45 16 $614
Gabapentin Generic 43 13 $455
Rosuvastatin Calcium Generic 43 14 $2,242
Metoprolol Succinate Generic 31 0 $1,277

Frequently asked questions

Auto-generated from federal data
What is Dr. Helen Chang's medical specialty?
Dr. Helen Chang practices Internal Medicine Physician in Mission Viejo, CA.
Where does Dr. Helen Chang practice?
Dr. Helen Chang practices at 25982 Pala, Mission Viejo, CA 926916719. Office phone: 9495880051.
What is Dr. Helen Chang's NPI?
Dr. Helen Chang's National Provider Identifier (NPI) is 1639134687, issued by NPPES.
What procedures does Dr. Helen Chang commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); Established patient office or other outpatient visit (HCPCS 99213); Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit (HCPCS G0439). Source: CMS Medicare Physician & Other Practitioners file.