Exhibit 99.1

MONTHLY SERVICER'S CERTIFICATE

CARMAX BUSINESS SERVICES, LLC

CARMAX AUTO OWNER TRUST

SERIES 2013-4



Collection Period		09/01/17-09/30/17
Determination Date		10/9/2017
Distribution Date		10/16/2017

Additional information, including defined terms, can be found in the prospectus on the SEC's EDGAR system (http://www.sec.gov) under File No. 333-189212-02.



Pool Balance
1.	Pool Balance on the close of the last day of the preceding Collection Period			$	128,894,510.39
2.	Collections allocable to Principal			$	9,083,523.00
3.	Purchase Amount allocable to Principal			$	0.00
4.	Defaulted Receivables			$	357,385.02
5.	Pool Balance on the close of the last day of the related Collection Period			$	119,453,602.37
	(Ln1 - Ln2 - Ln3 - Ln4)
6.	Total number of Receivables outstanding on the close of the last day of the related Collection Period			20,920
7.	Initial Pool Balance			$	1,000,000,005.06
		Beginning of Period		End of Period
8.	Note Balances
	a. Class A-1 Note Balance	$	0.00	$	0.00
	b. Class A-2 Note Balance	$	0.00	$	0.00
	c. Class A-3 Note Balance	$	0.00	$	0.00
	d. Class A-4 Note Balance	$	61,894,510.36	$	52,453,602.34
	e. Class B Note Balance	$	22,000,000.00	$	22,000,000.00
	f. Class C Note Balance	$	20,000,000.00	$	20,000,000.00
	g. Class D Note Balance	$	20,000,000.00	$	20,000,000.00
	h. Note Balance (sum a - g)	$	123,894,510.36	$	114,453,602.34
9.	Pool Factors
	a. Class A-1 Note Pool Factor	0.0000000		0.0000000
	b. Class A-2 Note Pool Factor	0.0000000		0.0000000
	c. Class A-3 Note Pool Factor	0.0000000		0.0000000
	d. Class A-4 Note Pool Factor	0.4485109		0.3800986
	e. Class B Note Pool Factor	1.0000000		1.0000000
	f. Class C Note Pool Factor	1.0000000		1.0000000
	g. Class D Note Pool Factor	1.0000000		1.0000000
	h. Note Pool Factor	0.1238945		0.1144536
10.	Overcollateralization Target Amount			$	5,000,000.03
11.	Current overcollateralization amount (Pool Balance - Note Balance)			$	5,000,000.03
12.	Weighted Average Coupon			7.50		%
13.	Weighted Average Original Term	months		68.57
14.	Weighted Average Remaining Term	months		19.47
Collections
15.	Finance Charges:
	a. Collections allocable to Finance Charge			$	830,800.32
	b. Liquidation Proceeds allocable to Finance Charge			$	5,424.31
	c. Purchase Amount allocable to Finance Charge			$	0.00
	d. Available Finance Charge Collections (sum a - c)			$	836,224.63
16.	Principal:
	a. Collections allocable to Principal			$	9,083,523.00
	b. Liquidation Proceeds allocable to Principal			$	194,651.66
	c. Purchase Amount allocable to Principal			$	0.00
	d. Available Principal Collections (sum a - c)			$	9,278,174.66



17.	Total Finance Charge and Principal Collections (15d + 16d)	$	10,114,399.29
18.	Interest Income from Collection Account	$	6,861.82
19.	Simple Interest Advances	$	0.00
20.	Available Collections (Ln17 + 18 + 19)	$	10,121,261.11
Available Funds
21.	Available Collections	$	10,121,261.11
22.	Reserve Account Draw Amount	$	0.00
23.	Available Funds	$	10,121,261.11
Application of Available Funds
24.	Servicing Fee
	a. Monthly Servicing Fee	$	107,412.09
	b. Amount Unpaid from Prior Months	$	0.00
	c. Amount Paid	$	107,412.09
	d. Shortfall Amount (a + b - c)	$	0.00
25.	Unreimbursed Servicer Advances	$	0.00
26.	Backup Servicing Fees and Unpaid Transition Expenses
	a. Monthly Servicing Fee	$	2,500.00
	b. Unpaid Transition Expenses and Indemnity Amounts (Capped at $175,000)	$	0.00
	c. Other Unpaid Backup Servicing Fees	$	0.00
	d. Amount Paid	$	2,500.00
	e. Shortfall Amount (a + b + c - d)	$	0.00
27.	Class A Noteholder Interest Amounts
	a. Class A-1 Monthly Interest	$	0.00
	b. Additional Note Interest related to Class A-1 Monthly Interest	$	0.00
	c. Interest Due on Additional Note Interest related to Class A-1 Monthly Interest	$	0.00
	d. Total Class A-1 Note Interest (sum a - c)	$	0.00
	e. Class A-2 Monthly Interest	$	0.00
	f. Additional Note Interest related to Class A-2 Monthly Interest	$	0.00
	g. Interest Due on Additional Note Interest related to Class A-2 Monthly Interest	$	0.00
	h. Total Class A-2 Note Interest (sum e - g)	$	0.00
	i. Class A-3 Monthly Interest	$	0.00
	j. Additional Note Interest related to Class A-3 Monthly Interest	$	0.00
	k. Interest Due on Additional Note Interest related to Class A-3 Monthly Interest	$	0.00
	l. Total Class A-3 Note Interest (sum i - k)	$	0.00
	m. Class A-4 Monthly Interest	$	66,020.81
	n. Additional Note Interest related to Class A-4 Monthly Interest	$	0.00
	o. Interest Due on Additional Note Interest related to Class A-4 Monthly Interest	$	0.00
	p. Total Class A-4 Note Interest (sum m - o)	$	66,020.81
28.	Priority Principal Distributable Amount	$	0.00
29.	Class B Noteholder Interest Amount
	a. Class B Monthly Interest	$	31,350.00
	b. Additional Note Interest related to Class B Monthly Interest	$	0.00
	c. Interest Due on Additional Note Interest related to Class B Monthly Interest	$	0.00
	d. Total Class B Note Interest (sum a - c)	$	31,350.00
30.	Secondary Principal Distributable Amount	$	0.00
31.	Class C Noteholder Interest Amount
	a. Class C Monthly Interest	$	32,500.00
	b. Additional Note Interest related to Class C Monthly Interest	$	0.00
	c. Interest Due on Additional Note Interest related to Class C Monthly Interest	$	0.00
	d. Total Class C Note Interest (sum a - c)	$	32,500.00
32.	Tertiary Principal Distributable Amount	$	0.00



33.	Class D Noteholder Interest Amount
	a. Class D Monthly Interest	$	43,333.33
	b. Additional Note Interest related to Class D Monthly Interest	$	0.00
	c. Interest Due on Additional Note Interest related to Class D Monthly Interest	$	0.00
	d. Total Class D Note Interest (sum a - c)	$	43,333.33
34.	Quaternary Principal Distributable Amount	$	4,440,907.99
35.	Required Payment Amount (Ln 24 + Ln 26 + (sum of Ln 27 through Ln 34))	$	4,724,024.22
36.	Reserve Account Deficiency	$	0.00
37.	Regular Principal Distributable Amount	$	5,000,000.03
38.	Remaining Unpaid Servicer Transition Expenses, if any	$	0.00
39.	Additional Servicing Fees, if any	$	0.00
40.	Remaining Unpaid Backup Servicer Indemnity Amounts, if any	$	0.00
Collection Account Activity
41.	Deposits
	a. Total Daily Deposits of Finance Charge Collections	$	836,224.63
	b. Total Daily Deposits of Principal Collections	$	9,278,174.66
	c. Withdrawal from Reserve Account	$	0.00
	d. Interest Income	$	6,861.82
	e. Total Deposits to Collection Account (sum a - d)	$	10,121,261.11
42.	Withdrawals
	a. Servicing Fee and Unreimbursed Servicer Advances	$	107,412.09
	b. Backup Servicing Fee and Unreimbursed Backup Servicer Advances	$	2,500.00
	c. Deposit to Note Payment Account for Monthly Note Interest/Principal	$	9,614,112.16
	d. Deposit to Reserve Account	$	0.00
	e. Excess Collections (Deposit to Certificate Payment Account for payment to Certificateholder)	$	397,236.86
	f. Total Withdrawals from Collection Account (sum a - e)	$	10,121,261.11
Note Payment Account Activity
43.	Deposits
	a. Class A-1 Interest Distribution	$	0.00
	b. Class A-2 Interest Distribution	$	0.00
	c. Class A-3 Interest Distribution	$	0.00
	d. Class A-4 Interest Distribution	$	66,020.81
	e. Class B Interest Distribution	$	31,350.00
	f. Class C Interest Distribution	$	32,500.00
	g. Class D Interest Distribution	$	43,333.33
	h. Class A-1 Principal Distribution	$	0.00
	i. Class A-2 Principal Distribution	$	0.00
	j. Class A-3 Principal Distribution	$	0.00
	k. Class A-4 Principal Distribution	$	9,440,908.02
	l. Class B Principal Distribution	$	0.00
	m. Class C Principal Distribution	$	0.00
	n. Class D Principal Distribution	$	0.00
	o. Total Deposits to Note Payment Account (sum a - n)	$	9,614,112.16
44.	Withdrawals
	a. Class A-1 Distribution	$	0.00
	b. Class A-2 Distribution	$	0.00
	c. Class A-3 Distribution	$	0.00
	d. Class A-4 Distribution	$	9,506,928.83
	e. Class B Distribution	$	31,350.00
	f. Class C Distribution	$	32,500.00
	g. Class D Distribution	$	43,333.33
	h. Total Withdrawals from Note Payment Account (sum a - g)	$	9,614,112.16



Certificate Payment Account Activity
45.	Deposits
	a. Excess Collections	$	397,236.86
	b. Reserve Account surplus (Ln 55)	$	1,895.30
	c. Total Deposits to Certificate Payment Account (sum a - b)	$	399,132.16
46.	Withdrawals
	a. Certificateholder Distribution	$	399,132.16
	b. Total Withdrawals from Certificate Payment Account	$	399,132.16
Required Reserve Account Amount
47.	Lesser of: (a or b)
	a. $2,500,000.02	$	2,500,000.02
	b. Note Balance	$	114,453,602.34
48.	Required Reserve Account Amount	$	2,500,000.02
Reserve Account Reconciliation
49.	Beginning Balance (as of end of preceding Distribution Date)	$	2,500,000.02
50.	Investment Earnings	$	1,895.30
51.	Reserve Account Draw Amount	$	0.00
52.	Reserve Account Amount (Ln 49 + Ln 50 - Ln 51)	$	2,501,895.32
53.	Deposit from Available Funds (Ln 42d)	$	0.00
54.	If Reserve Account Balance exceeds Required Reserve Account Amount, payment to
	a. the Note Payment Account for the payment of principal to the extent of any unfunded Regular Principal Distribution Amount; and	$	0.00
	b. any Successor Servicer for the payment of any unfunded Transition Costs and Additional Servicing Fee	$	0.00
55.	Payment to Certificateholder if Reserve Account Balance exceeds Required Reserve Account Amount and to the extent no unfunded amounts described in Ln 54 exist	$	1,895.30
56.	Ending Balance (Ln52 + Ln53 - Ln54 - Ln55)	$	2,500,000.02
57.	Reserve Account Deficiency (Ln48 - Ln56)	$	0.00
Instructions to the Trustee
58.	Amount to be deposited from the Reserve Account into the Collection Account	$	0.00
59.	Amount to be paid to Servicer from the Collection Account	$	107,412.09
60.	Amount to be paid to Backup Servicer from the Collection Account	$	2,500.00
61.	Amount to be deposited from the Collection Account into the Note Payment Account	$	9,614,112.16
62.	Amount to be deposited from the Collection Account into the Certificate Payment Account	$	397,236.86
63.	Amount to be deposited from the Collection Account into the Reserve Account	$	0.00
64.	Amount to be deposited from the Reserve Account, if Reserve Account Balance exceeds Required Reserve Account Amount, into
	a. the Note Payment Account for any unfunded Regular Principal Distributable Amount	$	0.00
	b. the Certificate Payment Account for payment to the Certificateholder, if no unfunded Regular Principal distributable amount exists	$	1,895.30
65.	Amount to be paid to Class A-1 Noteholders from the Note Payment Account	$	0.00
66.	Amount to be paid to Class A-2 Noteholders from the Note Payment Account	$	0.00
67.	Amount to be paid to Class A-3 Noteholders from the Note Payment Account	$	0.00
68.	Amount to be paid to Class A-4 Noteholders from the Note Payment Account	$	9,506,928.83
69.	Amount to be paid to Class B Noteholders from the Note Payment Account	$	31,350.00
70.	Amount to be paid to Class C Noteholders from the Note Payment Account	$	32,500.00
71.	Amount to be paid to Class D Noteholders from the Note Payment Account	$	43,333.33
72.	Amount to be paid to Certificateholders from the Certificate Payment Account with respect to Excess Collections and Reserve Account surplus	$	399,132.16



Delinquency Activity
		Number of Loans	Principal Balance
73.	Delinquency Analysis
	a. 31 to 60 days past due	611	$	5,132,891.32
	b. 61 to 90 days past due	225	$	1,895,572.86
	c. 91 to 120 days past due	64	$	536,273.85
	d. 121 or more days past due	0	$	0.00
	e. Total Past Due (sum a - d)	900	$	7,564,738.03
	f. Delinquent Loans as a percentage of end of period Pool Balance (Ln 73e / Ln 5)		6.3328		%

Loss Activity
		Number of Loans	Principal Balance

74.	Defaulted Receivables (charge-offs)	47	$	357,385.02
75.	Recoveries	181	$	200,075.97
76.	Net Losses (Ln 74 - Ln 75)		$	157,309.05
77.	Ratio of Net Losses to Beginning of Period Pool Balance (Ln 76 / Ln 1)		0.1220		%

Cumulative Loss Activity
		Number of Loans	Principal Balance

78.	Defaulted Receivables (charge-offs)	2,823	$	34,593,988.77
79.	Recoveries	2,518	$	17,215,860.69
80.	Cumulative Net Losses (Ln 78 - Ln 79)		$	17,378,128.08
81.	Ratio of Cumulative Net Losses to Initial Pool Balance (Ln 80 / Ln 7)		1.7378		%
82.	Average Net Loss on Defaulted Receivables		$	6,155.91

Servicer Covenant
83.	CarMax, Inc Consolidated Tangible Net Worth as of the end of the Related Fiscal Quarter		$	3,143,451,000.00
84.	Is CarMax, Inc Consolidated Tangible Net Worth greater than $1,000,000,000?		Yes

IN WITNESS WHEREOF, the undersigned has duly executed this certificate on October 9, 2017.



CARMAX BUSINESS SERVICES, LLC

As Servicer

By:	/s/ Enrique Mayor-Mora

Name:	Enrique Mayor-Mora

Title:	Vice President and Treasurer

CarMax Auto Owner Trust 2013-4 10-D