Dr. Daniel Alexander Leffler, MD

Dr. Leffler practices at Beth Israel Deaconess Medical Center in Boston, Massachusetts, part of Beth Israel Lahey Health.

Dr. Leffler's NPI, 1144368697, was assigned on February 4, 2007. Dr. Leffler holds Massachusetts license 223242.

Dr. Leffler's primary practice is Beth Israel Deaconess Medical Center, at 330 Brookline Avenue, Boston, MA 02215 in Suffolk County. The practice phone is (617) 667-7000.

Dr. Leffler's primary practice is Beth Israel Deaconess Medical Center in Boston, Massachusetts, part of Beth Israel Lahey Health. The medical group on file is Harvard Medical Faculty Physicians at Beth Israel Deaconess Medical Center (HMFP). Dmand AI also links Dr. Leffler to 1 more medical group, named with a free account.

Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Leffler practices. Vendor and product names are available with a free account.

Gastroenterology is Dr. Leffler's primary specialty in the NPI Registry, under taxonomy code 207RG0100X. Dr. Leffler is licensed in Massachusetts.

CMS data shows 16 Medicare services from Dr. Leffler across 1 procedure code in 2024, all of them office visits, for 22 Medicare patients. Medicare paid $1,056 for them. Every service was in a facility, such as a hospital, rather than an office.

CMS counts 22 Medicare patients who saw Dr. Leffler in 2024. 68% of them have high cholesterol, and 68% have osteoporosis. Their average risk score is 1.01, where 1.00 is the Medicare average.

Across all payers, Dmand AI patient panel data puts Dr. Leffler's median patient age at 50, with 83% women.

In 2024, Dr. Leffler wrote 57 Medicare Part D claims for 15 patients. 82% of them were for generic drugs. CMS names the drug for 18 of them, across 1 drug with 11 or more claims each, at $569 in total drug cost. In 2023, CMS named 17 claims across 1 drug.

Dr. Leffler accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Leffler as offering telehealth.

Dmand AI links 181 papers to Dr. Leffler, published from 2007 to 2025. 2017 was the busiest year, with 17. The most frequent topics are Celiac Disease, Diet, Gluten-Free and Glutens. Dr. Leffler has published most often in Aliment Pharmacol Ther. Dr. Leffler's most frequent co-authors are Joseph D. Feuerstein, MD, Benjamin Lebwohl, MD and Adam S. Cheifetz, MD.

Dmand AI links Dr. Leffler to 2 clinical trials. Conditions studied include Celiac Disease, Diabetes Mellitus, Type 2 and Diabetes Mellitus. Open Payments lists research payments to Dr. Leffler that name 1 trial.

CMS Open Payments shows 18 general payments to Dr. Leffler from 6 drug and device companies from 2016 to 2017. Consulting fees make up the largest share, 81% of the total. Phadia US Inc. paid the most, $4,898. It also lists 1 research payment totaling $3,025 in 2016, naming 1 clinical trial.