Doctor profile · Federal record

Dr. Siamak Milanchi, M.D.

Colon & Rectal Surgery Physician (CMS: Colorectal Surgery (Proctology)) · Surgery Physician · Irvine, CA

  • NPI 1083829956
  • Accepts Medicare
  • 30 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
16300 Sand Canyon Ave Ste 604
Irvine, CA 926183706
(949) 429-0268
fax (949) 420-2180
Mailing address
Po Box 52435
Irvine, CA 926192435

Credentials & registration

NPPES · NUCC
NPI registered
May 2007 — 19 yrs on file
Profile last updated
October 22, 2012
Year of graduation
1996 — 30 yrs since
Specialty taxonomy
208C00000X — NUCC code
State license (1)
California #A92723

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1083829956. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
200
Distinct HCPCS
3
Medicare allowed
$26,797
HCPCS Description Services Patients Avg allowed
99214 Established patient office or other outpatient visit, 30-39 minutes 100 63 $139
99203 New patient office or other outpatient visit, 30-44 minutes 54 54 $122
46600 Diagnostic exam of anus using an endoscope 46 41 $138

In context: peer comparison

Among 5 peers in Irvine Colon & Rectal Surgery Physician, average services per provider: 35. This provider delivers 5.7× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$33
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Baxter Healthcare 1 $33.45

By nature of payment

Food and Beverage
$33

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
25
Patients
23
Total drug cost
$443
Drug Type Claims Patients Total cost
Gavilyte-G (Peg3350/Sod Sulf,Bicarb,Cl/Kcl) Brand 25 23 $443

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Siamak Milanchi's medical specialty?
Dr. Siamak Milanchi practices Colon & Rectal Surgery Physician in Irvine, CA.
Where does Dr. Siamak Milanchi practice?
Dr. Siamak Milanchi practices at 16300 Sand Canyon Ave Ste 604, Irvine, CA 926183706. Office phone: 9494290268.
What is Dr. Siamak Milanchi's NPI?
Dr. Siamak Milanchi's National Provider Identifier (NPI) is 1083829956, issued by NPPES.
Does Dr. Siamak Milanchi accept Medicare assignment?
Yes. Dr. Siamak Milanchi accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Siamak Milanchi commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99214); New patient office or other outpatient visit (HCPCS 99203); Diagnostic exam of anus using an endoscope (HCPCS 46600). Source: CMS Medicare Physician & Other Practitioners file.