CCM 6-K

UNITED STATESSECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2026

Commission File Number: 001-34563

CONCORD MEDICAL SERVICES HOLDINGS LIMITED

Room A1-A5 26/F, East Zone, Hanwei Plaza

No. 7 Guanghua Road, Chaoyang District,

Beijing 100020

People’s Republic of China

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x Form 40-F ¨

Concord Healthcare Completed the Issue of Convertible Bonds

Concord Healthcare Group Co., Ltd. (“Concord Healthcare”), a subsidiary of Concord Medical Services Holdings Limited (the “Company”) (NYSE: CCM) and a company listed on the Main Board of The Stock Exchange of Hong Kong Limited (the “HKSE”) under the stock code 2453.HK, completed the issue of 2% convertible bonds due 2027 in the aggregate principal amount of HK$68 million on May 13, 2026, in accordance with the placing and subscription agreement dated May 10, 2026 with Haitong International Securities Company Limited as the placing agent and Dragon Merit Holdings Limited as the subscriber.

The Company previously announced the listing of Concord Healthcare’s H shares on the HKSE on January 9, 2024. The information related to Concord Healthcare’s annual report on the HKSE is accessible through the HKSE’s website at www.hkexnews.hk.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: May 13, 2026