UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act File Number: 811-05986

T. Rowe Price Index Trust, Inc.

(Exact name of registrant as specified in charter)

1307 Point Street, Baltimore, MD 21231

(Address of principal executive offices)

David Oestreicher

1307 Point Street, Baltimore, MD 21231

(Name and address of agent for service)

Registrant’s telephone number, including area code: (410) 345-2000

Date of fiscal year end: December 31

Date of reporting period: June 30, 2026

Item 1. Reports to Shareholders

(a) Report pursuant to Rule 30e-1

Item 1. (b) Notice pursuant to Rule 30e-3.

Not applicable.

Item 2. Code of Ethics.

A code of ethics, as defined in Item 2 of Form N-CSR, applicable to its principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions is filed as an exhibit to the registrant’s annual Form N-CSR. No substantive amendments were approved or waivers were granted to this code of ethics during the registrant’s most recent fiscal half-year.

Item 3. Audit Committee Financial Expert.

Disclosure required in registrant’s annual Form N-CSR.

Item 4. Principal Accountant Fees and Services.

Disclosure required in registrant’s annual Form N-CSR.

Item 5. Audit Committee of Listed Registrants.

Not applicable.

Item 6. Investments.

(a) Not applicable. The complete schedule of investments is included in Item 7 of this Form N-CSR.

(b) Not applicable.

Item 7. Financial Statements and Financial Highlights for Open-End Management Investment Companies.

(a – b) Report pursuant to Regulation S-X.