The information in this preliminary pricing supplement is not complete and may be changed. This preliminary pricing supplement is not an offer to sell these securities in any jurisdiction where the offer or sale is not permitted.

Subject to completion dated August 4, 2025

Filed under Rule 424(b)(3), Registration Statement No. 333-275151

Pricing Supplement No. 27 - Dated Monday, August 4, 2025 (To: Prospectus Dated October 24, 2023 and Prospectus Supplement Dated November 1, 2024)

CUSIP Number

Principal Amount

Selling Price

Gross Concession

Net Proceeds

Coupon Type

Coupon Rate

Coupon Frequency

Maturity Date

1st Coupon Date

1st Coupon Amount

Survivor's Option

Product Ranking

63743LA45

[ ]

100.000%

3.150%

[ ]

Fixed

5.750%

Semi- Annual

08/15/2055

02/15/2026

$28.91

Yes

Subordinated Notes

Redemption Information:

Callable at the Issuer’s option, in whole or from time to time in part, on any day on or after 08/15/2030 (the “Par Call Period”) at a redemption price in cash equal to 100% of the principal amount of the notes being redeemed, plus, accrued and unpaid interest, if any, thereon to, but excluding, the redemption date

			Offering Date: Monday, August 4, 2025 through Monday, August 11, 2025			National Rural Utilities Cooperative Finance Corp
National Rural Utilities Cooperative Finance Corp			Trade Date: Monday, August 11, 2025 @12:00 PM ET			Subordinated Notes (Subordinated Deferrable Interest Notes)
			Settle Date: Thursday, August 14, 2025
			Minimum Denomination/Increments:$1,000.00/$1,000.00			Prospectus dated October 24, 2023 and
			Initial trades settle flat and clear SDFS: DTC Book Entry only			Prospectus Supplement Dated: November 1, 2024
			DTC Number: 0235 via RBC Dain Rauscher Inc.
			Agents: InspereX LLC, Citigroup Global Markets Inc., RBC Capital Markets, LLC, Wells Fargo Clearing Services, LLC
			Trustee: U.S. Bank Trust Company, National Association
			Notes will be sold to you at the selling price specified in this Pricing Supplement. The Purchasing Agent shall purchase notes from us at the selling price less the applicable gross concession specified in this Pricing Supplement. The Purchasing Agent may resell the notes it purchases to the agents and selected dealers at the selling price less a concession that, at the discretion of the Purchasing Agent, may be less than or equal to the gross concession received by the Purchasing Agent. Notes purchased by the agents and selected dealers on behalf of level-fee [investment or advisory] accounts may be sold to such accounts at the selling price less the applicable concession, and such agents and selected dealers shall not retain, as compensation, any portion of such concession.