DBRS Limited (DBRS Morningstar) downgraded six classes of Commercial Mortgage Pass-Through Certificates, Series 2015-C21 issued by Morgan Stanley Bank of America Merrill Lynch Trust 2015-C21 as follows.

Class D at BB (high) (sf) from BBB (low) (sf)

Class X-E at B (high) (sf) from BB (sf)

Class E at B (sf) from BB (low) (sf)

Class F at B (low) (sf) from B (high) (sf)

Class X-FG at B (low) (sf) from B (sf)

Class G at CCC (sf) from B (low) (sf)

In addition, DBRS Morningstar confirmed the remaining classes as follows:

Class A-3 at AAA (sf)

Class A-4 at AAA (sf)

Class A-S at AAA (sf)

Class A-SB at AAA (sf)

Class X-A at AAA (sf)

Class X-B at AAA (sf)

Class B at AA (high) (sf)

Class C at A (sf)

Class PST at A (sf)

Class 555A at A (sf)

Class 555B at BBB (sf)

Classes D, E, F, G, X-E, and X-FG were removed from Under Review with Negative Implications, where they were placed on August 6, 2020. All trends are Stable, with the exception of Classes D, E, F, X-E, and X-FG, which have Negative trends. Class G has a rating that does not carry a trend, and DBRS Morningstar placed Interest in Arrears designations on Classes E, F, and G. The ratings downgrade and negative trends are due to the elevated risk profile of two of the largest loans in the pool that have been negatively affected by the Coronavirus Disease (COVID-19) pandemic, as well as the concentration of loans in special servicing, which represent 24.1% of the pool as of the November 2020 remittance. The pool has a high concentration of loans backed by retail properties, representing 32.8% of the pool balance. As retail properties have been severely affected by the coronavirus pandemic, this concentration indicates increased risks for the pool.

The Class 555A and Class 555B certificates are rake bonds backed by the 555 11th Street NW subordinate B note, which is a $57.0 million loan that composes a portion of the $177.0 million whole loan secured by the collateral property, a Class A office building in Washington, D.C. The whole loan comprises a $90.0 million pari passu A note ($60.0 million of which is held in the subject trust and backs the pooled bonds), a $30.0 million senior B note (not held in any commercial mortgage-backed securities transactions), and a $57.0 million subordinate B note, of which a $30.0 million pari passu portion was contributed to the subject transaction. The subordinate B note is below the senior B note in payment priority. The performance of the underlying collateral has been strong since issuance. As of June 2020, the servicer reported a 99.0% occupancy rate and a debt service coverage ratio (DSCR) of 2.39 times (x) and 1.37x on the A note and whole loan balances, respectively. The largest tenants are Latham & Watkins (58.1% of the net rentable area (NRA), expiring January 2031), Silver Cinemas (9.7% of the NRA, expiring March 2032), and the American Cancer Society (5.9% of the NRA, expiring October 2021). Given the strength in tenancy with minimal rollover in the near to moderate term, DBRS Morningstar considers the risks with this loan to be generally unchanged from issuance.

As of the November 2020 remittance, 62 of the original 64 loans remain in the pool, with scheduled amortization resulting in 8.9% of collateral reduction since issuance. Three loans, representing 3.8% of the current pool balance, are fully defeased. There are six loans in special servicing, including the largest loan in the pool, Westfield Palm Desert Mall (Prospectus ID#1, 7.9% of the pool balance), which is 90 to 120 days delinquent and is secured by a 572,724-sf portion of a 977,888-sf regional mall in Palm Desert, California. In addition, the loan reported approximately $612,434 in outstanding principal and interest advances. The loan transferred to special servicing in July 2020 for delinquent payments, with the servicer reporting they are dual tracking foreclosure while also negotiating with the borrower for a potential loan modification.

The mall anchors are Macy's, JCPenney, with a former Sears that was closed in early 2020. The largest collateral tenants include Dick's Sporting Goods, Tristone Cinemas, and Barnes & Noble. As of March 2020, the subject reported a DSCR of 1.58x, a decline compared with the YE2019 and YE2018 DSCR figures of 1.97x and 2.26x, respectively. Given the cash flow declines from issuance, as well as the dark anchor in Sears and the bankruptcy filing for JCPenney, the risks for this loan are significantly increased since issuance, particularly when considering the extended delinquency and possibility of foreclosure. As such, DBRS Morningstar liquidated the loan in the analysis for this review, with a loss severity in excess of 50.0%.

The second-largest loan in special servicing is Ashford Hotel Portfolio (Prospectus ID#4, 6.2% of the pool), which is secured by a portfolio of two extended-stay hotels and one limited-service hotel, located throughout Florida, Kansas, and Utah. The subject was transferred to special servicing in June 2020 for delinquent payments, and the servicer noted a loan modification is under review. The terms of the modification could include provisions allowing the borrower to pay 50.0% of debt service from April 2020 through April 2021. By May 2021, regular payments would continue and deferred amounts would be repaid over an 18-month period beginning January 2022. As of the August 2020 appraisal, the portfolio reported a value of $69.8 million, a relatively minor 5.6% decline compared with the issuance appraised value of $73.2 million. Given the delinquency and the challenges facing hotels amid the pandemic, DBRS Morningstar applied a probability of default penalty for this loan to increase the expected loss in the analysis for this review.

According to the November 2020 remittance, 15 loans are on the servicer's watchlist, representing 17.7% of the current pool balance. The servicer is monitoring these loans for various reasons, including a low DSCR or occupancy figure, tenant rollover risk, and/or pandemic-related forbearance requests.

ESG CONSIDERATIONS

A description of how DBRS Morningstar considers ESG factors within the DBRS Morningstar analytical framework and its methodologies can be found at: https://www.dbrsmorningstar.com/research/357792.

DBRS Morningstar materially deviated from its North American CMBS Insight Model when determining the ratings on Classes B, C, D, and PST as the quantitative results suggested a lower rating. The material deviations are warranted given the uncertain loan level event risk with the loans in special servicing and on the servicer's watchlist.

Classes X-A, X-B, X-E, and X-FG are interest-only (IO) certificates that reference a single rated tranche or multiple rated tranches The IO rating mirrors the lowest-rated applicable reference obligation tranche adjusted upward by one notch if senior in the waterfall.

All ratings are subject to surveillance, which could result in ratings being upgraded, downgraded, placed under review, confirmed, or discontinued by DBRS Morningstar.

DBRS Morningstar provides updated analysis and in-depth commentary in the DBRS Viewpoint platform for the following loans in the transaction:

Prospectus ID#1 - Westfield Palm Desert Mall (7.9% of the pool)

Prospectus ID#4 - Ashford Hotel Portfolio (6.2% of the pool)

Prospectus ID#5 - Fontainebleau Park Plaza (6.2% of the pool)

For complimentary access to this content, please register for the DBRS Viewpoint platform at www.viewpoint.dbrsmorningstar.com. The platform includes issuer and servicer data for most outstanding CMBS transactions (including non-DBRS Morningstar rated), as well as loan-level and transaction-level commentary for most DBRS Morningstar-rated and -monitored transactions.

Notes:

All figures are in U.S. dollars unless otherwise noted.

The principal methodology is North American CMBS Surveillance Methodology (March 6, 2020), which can be found on dbrsmorningstar.com under Methodologies & Criteria. For a list of the structured-finance-related methodologies that may be used during the rating process, please see the DBRS Morningstar Global Structured Finance Related Methodologies document, which can be found on dbrsmorningstar.com in the Commentary tab under Regulatory Affairs. Please note that not every related methodology listed under a principal structured finance asset class methodology may be used to rate or monitor an individual structured finance or debt obligation.

For more information regarding rating methodologies and Coronavirus Disease (COVID-19), please see the following DBRS Morningstar press release: https://www.dbrsmorningstar.com/research/357883.

For more information regarding structured finance rating methodologies and Coronavirus Disease (COVID-19), please see the following DBRS Morningstar press release: https://www.dbrsmorningstar.com/research/358308.

For more information regarding the structured finance rating approach and Coronavirus Disease (COVID-19), please see the following DBRS Morningstar press release: https://www.dbrsmorningstar.com/research/359905.

The related regulatory disclosures pursuant to the National Instrument 25-101 Designated Rating Organizations are hereby incorporated by reference and can be found by clicking on the link under Related Documents or by contacting us at info@dbrsmorningstar.com.

The rated entity or its related entities did participate in the rating process for this rating action. DBRS Morningstar had access to the accounts and other relevant internal documents of the rated entity or its related entities in connection with this rating action.

Please see the related appendix for additional information regarding the sensitivity of assumptions used in the rating process. Please note a sensitivity analysis is not performed for CMBS bonds rated CCC or lower. The DBRS Morningstar long-term rating scale definition indicates that ratings of CCC or lower are assigned when the bond is highly likely to default or default is imminent, thereby prevailing over a sensitivity analysis.

Generally, the conditions that lead to the assignment of a Negative or Positive trend are generally resolved within a 12-month period. DBRS Morningstar's outlooks and ratings are monitored.

For more information on this credit or on this industry, visit www.dbrsmorningstar.com or contact us at info@dbrsmorningstar.com.

DBRS Limited

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Toronto, ON M5H 3M7 Canada

Tel. +1 416 593-5577

Ratings

Date Issued	Debt Rated	Action	Rating	Trend	Issued

i

US = USA Issued, NRSRO

CA = Canada Issued, NRSRO

EU = EU Issued, NRSRO

E = EU endorsed

Unsolicited Participating With Access

Unsolicited Participating Without Access

Unsolicited Non-Participating

02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class A-3	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class A-4	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class A-S	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class A-SB	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class X-A	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class X-B	Confirmed	AAA (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class B	Confirmed	AA (high) (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class 555A	Confirmed	A (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class C	Confirmed	A (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class PST	Confirmed	A (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class 555B	Confirmed	BBB (sf)	Stb	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class D	Downgraded	BB (high) (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class X-E	Downgraded	B (high) (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class E	Int. in Arrears	B (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class E	Downgraded	B (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class F	Int. in Arrears	B (low) (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class F	Downgraded	B (low) (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class X-FG	Downgraded	B (low) (sf)	Neg	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class G	Downgraded	CCC (sf)	--	CA
02-Dec-20	Commercial Mortgage Pass-Through Certificates, Series 2015-C21, Class G	Int. in Arrears	CCC (sf)	--	CA

ALL DBRS RATINGS ARE SUBJECT TO DISCLAIMERS AND CERTAIN LIMITATIONS. PLEASE READ THESE DISCLAIMERS AND LIMITATIONS AND ADDITIONAL INFORMATION REGARDING DBRS RATINGS, INCLUDING DEFINITIONS, POLICIES, RATING SCALES AND METHODOLOGIES.

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