Doctor profile · Federal record

Dr. Rena Callahan, M.D.

Internal Medicine Physician (CMS: Hematology/Oncology) · Hematology (Internal Medicine) Physician · Medical Oncology Physician · Surgical Oncology Physician · Valencia, CA

  • NPI 1487856779
  • Accepts Medicare
  • MIPS 84.9 / 100 · 2023
  • 22 yrs in practice
  • Female
  • Group practice
  • No sanctions

Practice & contact

Operates at 3 locations .

NPPES Updated May 11, 2026
Primary practice
27235 Tourney RD Ste 2400
Valencia, CA 913555905
(661) 255-5350
fax (661) 255-9907
Additional location
2020 Santa Monica Blvd Ste 230
Santa Monica, CA 904042124
(310) 829-5471
fax (310) 582-6294
Additional location
2336 Santa Monica Blvd Ste 315
Santa Monica, CA 904042095
(310) 829-5471
fax (310) 829-6192
Mailing address
5767 W Century Blvd Ste 400
Los Angeles, CA 900455631

Credentials & registration

NPPES · NUCC
NPI registered
May 2007 — 19 yrs on file
Profile last updated
January 23, 2020
Year of graduation
2004 — 22 yrs since
Specialty taxonomy
207R00000X — NUCC code
State license (1)
California #A94238

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1487856779. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
21,636
Distinct HCPCS
10
Medicare allowed
$465,506
HCPCS Description Services Patients Avg allowed
J1453 Injection, fosaprepitant, 1 mg 7,200 11 $0
J0897 Injection, denosumab, 1 mg 6,060 36 $23
J9394 Injection, fulvestrant (fresenius kabi) not therapeutically equivalent to j9395, 25 mg 1,740 18 $18
99214 Established patient office or other outpatient visit, 30-39 minutes 1,053 402 $140
J1100 Injection, dexamethasone sodium phosphate, 1 mg 835 18 $0
J2469 Injection, palonosetron hcl, 25 mcg 830 16 $1
J2405 Injection, ondansetron hydrochloride, per 1 mg 692 18 $0
J7050 Infusion, normal saline solution, 250 cc 460 92 $1
85025 Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count 454 139 $8
96375 Injection of additional new drug or substance into vein 304 37 $18

In context: peer comparison

Among 9 peers in Valencia Internal Medicine Physician, average services per provider: 291. This provider delivers 74× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$96,801
Transactions
92
Manufacturers
7
Payer (manufacturer) Industry Txns Amount
Gilead Sciences, INC. 55 $57,864.06
Stemline Therapeutics INC. 11 $13,719.65
AstraZeneca Pharmaceuticals Lp 9 $7,607.22
Pfizer INC. 6 $7,250.06
Daiichi Sankyo INC. 6 $5,332.09
Lilly USA, LLC 2 $2,812.50
Novartis Pharmaceuticals Corporation 3 $2,215.61

By nature of payment

Compensation for Services Other Than Consulting, Including Serving As Faculty or As A Speaker at A Venue Other Than A Continuing Education Program
$73,468
Travel and Lodging
$16,375
Consulting Fee
$3,910
Food and Beverage
$2,699
Grant
$350

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
582
Patients
126
Total drug cost
$1,654,354
Drug Type Claims Patients Total cost
Anastrozole Generic 204 67 $6,025
Tamoxifen Citrate Generic 55 25 $1,957
Eliquis (Apixaban) Brand 51 0 $35,018
Letrozole Generic 43 12 $1,400
Verzenio (Abemaciclib) Brand 42 0 $665,768
Exemestane Generic 26 11 $7,341
Gammagard Liquid (Immun Glob G(Igg)/Gly/Iga Ov50) Brand 25 0 $143,030
Calquence (Acalabrutinib Maleate) Brand 21 0 $292,691
Hydroxyurea Generic 20 0 $685
Kisqali (Ribociclib Succinate) Brand 20 0 $268,254

Hospital affiliations

CMS Hospital Compare

Frequently asked questions

Auto-generated from federal data
What is Dr. Rena Callahan's medical specialty?
Dr. Rena Callahan practices Internal Medicine Physician in Valencia, CA.
Where does Dr. Rena Callahan practice?
Dr. Rena Callahan practices at 27235 Tourney RD Ste 2400, Valencia, CA 913555905. Office phone: 6612555350.
What is Dr. Rena Callahan's NPI?
Dr. Rena Callahan's National Provider Identifier (NPI) is 1487856779, issued by NPPES.
Does Dr. Rena Callahan accept Medicare assignment?
Yes. Dr. Rena Callahan accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Rena Callahan commonly perform?
Top Medicare-reported procedures in 2023: Injection, fosaprepitant, 1 mg (HCPCS J1453); Injection, denosumab, 1 mg (HCPCS J0897); Injection, fulvestrant (fresenius kabi) not therapeutically equivalent to j9395, 25 mg (HCPCS J9394). Source: CMS Medicare Physician & Other Practitioners file.