Filed under Rule 424(b)(2), Registration Statement No. 333-218881

Preliminary Pricing Supplement No. 21 - Dated Monday, May 7, 2018 (To: Prospectus dated June 21, 2017)

CUSIP

Selling

Gross

Net

Principal

Coupon

Coupon

Coupon

Maturity

1st Coupon

1st Coupon

Survivor's

Product

Guarantor

Number

Price

Concession

Proceeds

Amount

Type

Rate

Frequency

Date

Date

Amount

Option

Ranking

37046ABQ7

100%

0.825%

[]

[]

Fixed

3.450%

SEMI-ANNUAL

05/20/2021

11/20/2018

$17.54

Yes

Senior Unsecured Notes

AmeriCredit Financial Services, Inc.

Redemption Information: Callable at 100% on 5/20/2019 and Semi-Annually thereafter with 30 Calendar Days Notice. GM Financial Term Notes will be subject to redemption at the option of General Motors Financial Company, Inc., in whole on the interest payment date occurring any time on or after 5/20/2019 at a redemption price equal to 100% of the principal amount of the GM Financial Term Notes, plus accrued interest thereon, if any, upon at least 30 Calendar Days prior notice to the noteholder and the trustee, as described in the Prospectus.

37046ABR5

100%

1.350%

[]

[]

Fixed

4.200%

SEMI-ANNUAL

05/20/2024

11/20/2018

$21.35

Yes

Senior Unsecured Notes

AmeriCredit Financial Services, Inc.

Redemption Information: Callable at 100% on 5/20/2019 and Semi-Annually thereafter with 30 Calendar Days Notice. GM Financial Term Notes will be subject to redemption at the option of General Motors Financial Company, Inc., in whole on the interest payment date occurring any time on or after 5/20/2019 at a redemption price equal to 100% of the principal amount of the GM Financial Term Notes, plus accrued interest thereon, if any, upon at least 30 Calendar Days prior notice to the noteholder and the trustee, as described in the Prospectus.

	Offering Dates: Monday, May 7, 2018 through Monday, May 14, 2018	General Motors Financial Company, Inc.
	Trade Date: Monday, May 14, 2018 @ 12:00 PM ET	GM Financial Term Notes
	Settlement Date: Thursday, May 17, 2018	Prospectus dated June 21, 2017
	Minimum Denomination/Increments: $1,000/$1,000
General Motors Financial Company, Inc.	Initial trades settle flat and clear SDFS: DTC Book Entry only
	DTC Number: 0235 via RBC Dain Rauscher Inc.
	Purchasing Agent: Incapital LLC
	Agents: BofA Merrill Lynch, Morgan Stanley, RBC Capital Markets, Wells Fargo Advisors
	Trustee: U.S. Bank National Association
	If the maturity date or an interest payment date for any note is not a Business Day (as term is defined in Prospectus), principal, premium, if any, and interest for that note is paid on the next Business Day, and no interest will accrue from, and after, the maturity date or interest payment date.
	Dealers purchasing Notes on an agency basis for client accounts shall purchase Notes at the public offering price. Notes sold by the Selected Dealers for their own account may be sold at the public offering price less a discount as specified above. Notes purchased by the Selected Dealers on behalf of level fee accounts may be sold to such accounts at the discount to the public offering price specified above, in which case, such Selected Dealers will not retain any portion of the sales price as compensation.