• Transfer Agent for NorthWestern Energy Common Stock
  Computershare
  211 Quality Circle, Suite 210
  College Station, TX 77845
  Toll Free Phone: 1 + (800) 368-5948
  Internet address: https://www.computershare.com

• CUSIP Numbers for NorthWestern Energy
  Common Stock
  668074305 (common stock) 

• Common Stock Dividend Policy
  NorthWestern Energy currently pays a quarterly dividend of 60 cents per share on the common stock. The anticipated dividend payment dates are March 31, June 30, September 30 and December 31.
  
  
• Stock Purchase
  NorthWestern Energy offers a Dividend Reinvestment and Direct Stock Purchase Plan which is administered by ComputerShare.
  
  
• Analyst Coverage
  
  Bank of America Merrill Lynch
  Julien Dumoulin-Smith
  (646) 855-5855
  julien.dumoulin-smith@baml.com
  
  Barclays
  Eric Beaumont
  (312) 609-8185
  eric.beaumont@barclays.com

Credit Suisse       
Michael Weinstein
(212) 325-0897
w.weinstein@credit-suisse.com

Guggenheim                
Shahriar Pourreza, CFA
(212) 518-5862 
shahriar.pourreza@guggenheimpartners.com
    
KeyBanc Capital Markets                 
Sophie Karp 
(917) 368-2361 
sophie.karp@key.com   

Sidoti & Company, LLC                 
Brian J. Russo, CFA
(212) 894-3357 
brusso@sidoti.com 

Value Line Publishing
Paul Debbas
(212) 907-1724
pdebbas@valueline.com
 
 Siebert Williams Shank & Co., LLC
 Christopher R. Ellinghaus
 (212) 373-4288
 cellinghaus@siebertwilliams.com

 Wells Fargo Securities, LLC
 Jonathon Reeder
 (314) 875-2052
 jonathon.reeder@wellsfargo.com 

• Debt Credit Ratings
  
  Standard & Poor's
  Senior Secured: A-
  Senior Unsecured: BBB
  Commercial Paper: A-2
  Outlook: Stable
  
  Moody's Investors Service
  Senior Secured: A3
  Senior Unsecured:  Baa2
  Commercial Paper: Prime-2
  Outlook:  Stable
   
  Fitch Ratings
  Senior Secured: A
  Senior Unsecured: A-
  Commercial Paper: F2
  Outlook: Stable
  
  

• General Mortgage Bonds
  5.01% First Mortgage Bonds (MT), due 5/1/2025, CUSIP 668074B*7
  5.01% First Mortgage Bonds (SD), due 5/1/2025, CUSIP 668074B@5
  3.11% First Mortgage Bonds (MT), due 7/1/2025, CUSIP 668074E@2 
  2.80% First Mortgage Bonds (SD) due 6/15/2026, CUSIP 668074F@1
  2.66% First Mortgage Bonds (SD) due 9/30/2026, CUSIP 668074F#9
  3.99% First Mortgage Bonds (MT), due 12/19/2028, CUSIP 668074D*5
3.21% First Mortgage Bonds (MT), due 5/15/2030, CUSIP 668074H*1
3.21% First Mortgage Bonds (SD) due 5/15/2030, CUSIP 668074H@9
5.71% First Mortgage Bonds, due 10/15/2039, CUSIP 668074A#4
4.26% First Mortgage Bonds (SD), due 9/29/2040, CUSIP 668074F*3
4.15% First Mortgage Bonds (MT), due 8/10/2042, CUSIP 668074B#3
4.15% First Mortgage Bonds (SD), due 8/10/2042, CUSIP 668074C@4
4.85% First Mortgage Bonds (MT), due 12/19/2043, CUSIP 668074D@3
4.85% First Mortgage Bonds (SD), due 8/10/2043, CUSIP 668074D#1
4.176% First Mortgage Bonds (MT), due 11/15/2044, CUSIP 668074AU1
4.22% First Mortgage Bonds (SD), due 12/19/2044, CUSIP 668074E*4
4.11% First Mortgage Bonds (MT), due 7/1/2045, CUSIP 668074E#0
4.03% First Mortgage Bonds (MT), due 11/6/2047 CUSIP 668074G*2
3.98% First Mortgage Bonds (MT), due 6/26/2049, CUSIP 668074G@0

• Pollution Control Bonds
  2.00% City of Forsyth, MT Pollution Control Bond, due 8/1/2023  

• Investor Contacts
  
  Analyst Inquiries
  Travis Meyer
  Director of Corporate Finance & Investor Relations Officer
  Phone: (605) 978-2967
  Fax: (605) 978-2910
  travis.meyer@northwestern.com
  
  Broker/Shareholder Inquiries
  Investor Relations Department
  Phone: (605) 978-2945
  Fax: (605) 978-2910
  
  Media Inquiries
  Jo Dee Black
  Manager External Communications
  Phone: (866) 622-8081
  Fax: (406) 444-8103
  jodee.black@northwestern.com