UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington D.C. 20549

FORM 10-D

ASSET BACKED ISSUER
DISTRIBUTION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

For the monthly distribution period from: ~~June~~July 18, 2025 to ~~July~~August 1715, 2025

Commission File Number of issuing entity: 333-206677-15

Central Index Key Number of issuing entity: 0001698685

BANK 2017-BNK4
(Exact name of issuing entity as specified in its charter)

Commission File Number of depositor: 333-206677

Central Index Key Number of depositor: 0000850779

Wells Fargo Commercial Mortgage Securities, Inc.
(Exact name of depositor as specified in its charter)

Central Index Key Number of sponsor (if applicable): 0000740906

Wells Fargo Bank, National Association
(Exact name of sponsor as specified in its charter)

Central Index Key Number of sponsor (if applicable): 0001102113

Bank of America, National Association
(Exact name of sponsor as specified in its charter)

Central Index Key Number of sponsor (if applicable): 0001541557

Morgan Stanley Mortgage Capital Holdings LLC
(Exact name of sponsor as specified in its charter)

Anthony Sfarra (212) 214-5600
(Name and telephone number, including area code, of the person to contact in connection with this filing)

New York
(State or other jurisdiction of incorporation or organization of the issuing entity)

38-4032075
38-4032076
38-7170551
(I.R.S. Employer Identification No.)

c/o Computershare Trust Company, N.A., as agent for
Wells Fargo Bank, National Association
9062 Old Annapolis Road
Columbia, MD 21045
(Address of principal executive offices of the issuing entity) (Zip Code)

(667) 786-1992
(Telephone number, including area code)

Not Applicable
(Former name, former address, if changed since last report)

Registered/reporting pursuant to (check one)

Title of Class	Section 12(b)	Section 12(g)	Section 15(d)	Name of Exchange (If Section 12(b))
A-1			X
A-2			X
A-SB			X
A-3			X
A-4			X
X-A			X
X-B			X
A-S			X
B			X
C			X

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes X No

Part I - DISTRIBUTION INFORMATION

Item 1. Distribution and Pool Performance Information.

On ~~July~~August 1715, 2025 a distribution was made to holders of the certificates issued by BANK 2017-BNK4.

The distribution report is attached as an Exhibit to this Form 10-D, please see Item 10(b), Exhibit 99.1 for the related information.

NoThe ~~assets~~following ~~securitized~~table bypresents ~~Wells~~the ~~Fargo~~loss ~~Commercial~~information ~~Mortgage~~for ~~Securities, Inc. (~~the ~~"Depositor")~~trust ~~and~~assets ~~held~~for bythe BANK 2017-BNK4 ~~were~~in ~~the~~accordance ~~subject~~with ofItem a1100(b) ~~demand~~as torequired ~~repurchase~~by orItem ~~replace~~1121(a)(9) ~~for breach~~ of ~~the~~Regulation ~~representations~~AB: ~~and warranties contained in the underlying transaction documents during the monthly distribution period from June 18, 2025 to July 17, 2025.~~

TheLoss DepositorInformation filedas itsreported most recent Form ABS-15G in accordance with Rule 15Ga-1 under the Securities Exchange Act of 1934 (a "Rule 15Ga-1 Form ABS-15G") on MayAugust 915, 2025. The CIK number for the Depositor is 0000850779.

Wells Fargo Bank, National Association ("Wells Fargo"), one of the sponsors, most recently filed a Rule 15Ga-1 Form ABS-15G on February 6, 2025. The Central Index Key number for Wells Fargo is 0000740906.

Number of Delinquencies 30+ days	% of Delinquencies 30+ days by Pool Balance	Number of Loans/REOs with Losses	Average Net Loss
1	8.14%	0	N/A

~~Bank~~No ofassets ~~America,~~securitized ~~National~~by ~~Association~~Wells Fargo Commercial Mortgage Securities, Inc. (~~"Bank~~the ~~of America~~"Depositor"), ~~one~~and ofheld ~~the~~by ~~sponsors,~~BANK ~~most~~2017-BNK4 were ~~recently~~the ~~filed~~subject of a ~~Rule~~demand ~~15Ga-1~~to ~~Form~~repurchase ~~ABS-15G~~or onreplace ~~May~~for 9,breach ~~2025.~~of ~~The~~the ~~Central~~representations ~~Index~~and ~~Key~~warranties ~~number~~contained ~~for Bank~~in ofthe ~~America~~underlying transaction documents during the monthly distribution period from July 18, 2025 isto August ~~0001102113~~15, 2025.

~~Morgan~~The ~~Stanley~~Depositor ~~Mortgage~~filed ~~Capital~~its ~~Holdings~~most ~~LLC ("Morgan~~recent ~~Stanley"),~~Form ~~one~~ABS-15G ofin accordance with Rule 15Ga-1 under the ~~sponsors,~~Securities ~~most~~Exchange ~~recently~~Act ~~filed~~of 1934 (a "Rule 15Ga-1 Form ABS-15G") on ~~May~~August 137, 2025. The ~~Central~~CIK ~~Index Key~~ number for ~~Morgan~~ ~~Stanley~~ the Depositor is ~~0001541557~~0000850779.

~~Item~~Wells ~~1A.~~Fargo ~~Asset~~Bank, National Association ("Wells Fargo"), one of the sponsors, most recently filed a Rule 15Ga-~~Level~~1 ~~Information~~Form ABS-15G on February 6, 2025. The Central Index Key number for Wells Fargo is 0000740906.

~~ABS~~Bank ~~Asset~~of ~~Data~~America, ~~File~~National Association (~~filed~~"Bank asof ~~Exhibit~~America"), ~~102~~one toof the ~~registrant's~~sponsors, most recently filed a Rule 15Ga-1 Form ABS-EE15G ~~filed~~ on ~~July~~August 298, 2025 ~~under~~. ~~Commission~~The ~~File~~Central ~~No.~~Index ~~333-206677-15~~Key ~~and~~number ~~incorporated~~for Bank byof ~~reference~~America is ~~herein)~~0001102113.

~~ABS~~Morgan ~~Asset~~Stanley ~~Related~~Mortgage ~~Document~~Capital Holdings LLC (~~filed~~"Morgan asStanley"), ~~Exhibit~~one ~~103~~of to the ~~registrant's~~sponsors, most recently filed a Rule 15Ga-1 Form ABS-EE15G ~~filed~~ on ~~July~~August 2912, 2025 ~~under~~. ~~Commission~~The ~~File~~Central ~~No.~~Index ~~333-206677-15~~Key ~~and~~number ~~incorporated~~for Morgan byStanley is ~~reference herein)~~0001541557.

~~Part~~Item II1A. Asset-Level ~~OTHER~~Information. ~~INFORMATION~~

~~Item~~ABS 7.Asset ~~Change~~Data inFile ~~Sponsor~~(filed ~~Interest~~as inExhibit 102 to the ~~Securities~~registrant's Form ABS-EE filed on August 28, 2025 under Commission File No. 333-206677-15 and incorporated by reference herein).

~~None~~ABS Asset Related Document (filed as Exhibit 103 to the registrant's Form ABS-EE filed on August 28, 2025 under Commission File No. 333-206677-15 and incorporated by reference herein).

~~Item~~Part 9.II ~~Other~~- ~~Information.~~OTHER INFORMATION

~~Trimont~~Item ~~LLC,~~7. Change in ~~its~~Sponsor ~~capacity~~Interest ~~as Master Servicer for BANK 2017-BNK4, affirms the following amounts~~ in the ~~respective~~Securities. ~~accounts:~~

Collection Account Balance
Prior Distribution Date	06/17/2025	$0.00
Current Distribution Date	07/17/2025	$0.00

None

*REO Account Balance
Prior Distribution Date	06/17/2025	$0.00
Current Distribution Date	07/17/2025	$0.00
*As provided by Special Servicer

Item 9. Other Information.

~~Computershare~~Trimont ~~Trust Company~~LLC, ~~N.A., as agent for Wells Fargo Bank, N.A.,~~ in its capacity as ~~Certificate~~Master ~~Administrator~~Servicer for BANK 2017-BNK4, affirms the following amounts in the respective accounts:

Distribution Account Balance
Collection Account Balance
Prior Distribution Date	0607/17/2025	$~~4,587~~0.5800
Current Distribution Date	0708/1715/2025	$~~4,425~~0.2800

Interest Reserve Account Balance
*REO Account Balance
Prior Distribution Date	0607/17/2025	$0.00
Current Distribution Date	0708/1715/2025	$0.00
*As provided by Special Servicer

Gain-on-Sale Reserve Account Balance
Prior Distribution Date	06/17/2025	$0.00
Current Distribution Date	07/17/2025	$0.00

Computershare Trust Company, N.A., as agent for Wells Fargo Bank, N.A., in its capacity as Certificate Administrator for BANK 2017-BNK4, affirms the following amounts in the respective accounts:

Item 10. Exhibits.

Distribution Account Balance
Prior Distribution Date	07/17/2025	$4,425.28
Current Distribution Date	08/15/2025	$4,577.18

(a) The following is a list of documents filed as part of this Report on Form 10-D:

Interest Reserve Account Balance
Prior Distribution Date	07/17/2025	$0.00
Current Distribution Date	08/15/2025	$0.00

(99.1) Monthly report distributed to holders of the certificates issued by BANK 2017-BNK4, relating to the July 17, 2025 distribution.

Gain-on-Sale Reserve Account Balance
Prior Distribution Date	07/17/2025	$0.00
Current Distribution Date	08/15/2025	$0.00

~~(102) ABS~~Item ~~Asset Data File (filed as Exhibit 102 to the registrant's Form ABS-EE filed on July 29, 2025 under Commission File No~~10. ~~333-206677-15 and incorporated by reference herein)~~Exhibits.

(~~103~~a) ~~ABS~~ ~~Asset~~The ~~Related~~following ~~Document~~is ~~(filed~~a aslist ~~Exhibit~~of ~~103~~documents tofiled ~~the~~as ~~registrant's~~part ~~Form~~of ~~ABS-EE~~this ~~filed~~Report on ~~July~~Form ~~29, 2025 under Commission File No. 333~~10-~~206677-15~~D: ~~and incorporated by reference herein).~~

(b99.1) ~~The~~ Monthly ~~exhibits~~report ~~required~~distributed to beholders ~~filed~~of the certificates issued by ~~the~~BANK ~~Registrant~~2017-BNK4, ~~pursuant~~relating to ~~this~~the ~~Form~~August ~~are~~15, ~~listed above~~2025 distribution.

~~SIGNATURES~~(102) ABS Asset Data File (filed as Exhibit 102 to the registrant's Form ABS-EE filed on August 28, 2025 under Commission File No. 333-206677-15 and incorporated by reference herein).

~~Pursuant~~(103) ABS toAsset ~~the~~Related ~~requirements~~Document of(filed ~~the~~as ~~Securities~~Exhibit ~~Exchange~~103 ~~Act~~to ~~of 1934,~~ the registrant's ~~has~~Form ~~duly~~ABS-EE ~~caused~~filed ~~this~~on ~~report~~August to28, be2025 ~~signed~~under onCommission ~~its~~File ~~behalf~~No. by333-206677-15 ~~the~~and ~~undersigned~~incorporated ~~thereunto~~by ~~duly~~reference ~~authorized~~herein).

~~Wells~~(b) ~~Fargo~~The ~~Commercial~~exhibits ~~Mortgage~~required ~~Securities,~~to ~~Inc~~be filed by the Registrant pursuant to this Form are listed above.~~(Depositor)~~

~~/s/ Anthony J. SfarraAnthony J. Sfarra, President~~SIGNATURES

~~Date: July~~Pursuant 29to the requirements of the Securities Exchange Act of 1934, ~~2025~~the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Wells Fargo Commercial Mortgage Securities, Inc.
(Depositor)

/s/ Anthony J. Sfarra
Anthony J. Sfarra, President

Date: August 28, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D.C. 20549

FORM 10-D

ASSET BACKED ISSUER DISTRIBUTION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Registered/reporting pursuant to (check one)

TheLoss DepositorInformation filedas itsreported most recent Form ABS-15G in accordance with Rule 15Ga-1 under the Securities Exchange Act of 1934 (a "Rule 15Ga-1 Form ABS-15G") on MayAugust 915, 2025. The CIK number for the Depositor is 0000850779.

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington D.C. 20549

ASSET BACKED ISSUER
DISTRIBUTION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

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