Guarantee Mortgage - San Francisco, 505 Montgomery

We have helped Bay Area families finance their home purchase, with over $2 billion in loans annually, and we can help you.

Offering a wide range of products and services, Guarantee Mortgage is well prepared to meet every real estate lending need.

We have 22 years under our belt providing world-class client service. Our top priority is to make sure you are presented with all available loan options, so that you can make an informed decision, that’s right for your financial situation.

Guarantee Mortgage NMLS #1850 and CAL-BRE License #01215943


Recommendations (936)

Aug 11, 2018

David Brant recommends Kathy Derangi

As first-time homebuyers, Kathy was an exceptional mortgage broker for us. She laid out a very clear financing path for us given our budget and down payment, and she was transparent with us on what we would get approved for. Kathy was on top of everything when it came to loan pre-approval, and more importantly the very tight Close of Escrow period. My fiancé and I highly recommend Kathy for any first-time homebuyers in the SF market.
Aug 8, 2018

Wyatt Hunter recommends Aisling Ferguson

She's the best - very clear, very concise, very friendly and very helpful. Made the mortgage process as smooth as possible and was flexible when I had a funding hiccup along the way.
Aug 7, 2018

Claudia Natasia recommends James W. Argo

UX Researcher

Jim was very responsive and knowledgeable. He made the process of purchasing our first home very easy for us. You can always count on him to answer any questions you have immediately. I highly recommend his services.
Aug 1, 2018

Chris recommends Larry Horowitz

08/01/2018 Larry is professional, reliable and went to great lengths to make our loan process run smoothly. He is very attentive to detail, and quickly responded to phone calls and emails. He went out of his way to communicate with our realtor, escrow officer and even the seller when questions needed answering. We have used Larry for multiple real estate transactions and highly recommend his services.
Aug 1, 2018

Carl recommends Larry Horowitz

08/01/2018 I've been working with Larry for over 25 years now, and he has always been helpful and reliable. He went above and beyond the call of duty for this recent transaction. He was creative, patient, and persistent. Not many lenders could have helped me in the way Larry did.
Jul 31, 2018

Anonymous recommends Kathy Derangi

Very helpful and efficient
Jul 31, 2018

Michelle W recommends Aisling Ferguson

As a first time home buyer in the bay area, Aisling made the loan process incredibly easy and painless for me. I have nothing but good things to say about the way she works and her ability to make things happen in a timely and efficient manner. She was highly communicative every step of the way, and I never had to followup with her as she was always following up with me. While extremely busy, she also never failed to leave time for me and reminded me to reach out with questions or concerns even on weekends. I fully endorse working with Aisling and look forward to doing so again in the future.
Jul 30, 2018

Abraham Zachariah recommends Kathy Derangi

Very customer service oriented and efficient
Jul 30, 2018

Robert Mayer recommends Aisling Ferguson

Realtor Associate at Hill & Co San Francisco

I have worked exclusively with Aisling for all my clients mortgage needs for over 20 years. Aisling has consistently under promised and over delivered each and every time I have sent a client to her. Even with the more challenging lending situations, she has always performed with a laser focus on delivering results.
I highly recommend Aisling !
Jul 27, 2018

Cy Berlowitz recommends Aisling Ferguson

"Aisling Ferguson assisted us in obtaining two loans to help us purchase a condo for our daughter in San Francisco. It was a complicated transaction but Aisling sailed through it like like the consumate professional that she is. Besides, she held our hands all the way through the transactions.until its completion. Our daughter is now the proud owner of a San Francisco condo, and we couldn't be happier. Anyone needing assistance with a loan would be fortunate to use Aisling Ferguson.

Sincerely Yours,

Cy Berlowitz
Jul 26, 2018

Laila Zachariah recommends Kathy Derangi

Exceptional!!! The very best experience.
Jul 24, 2018

Procie Sichon recommends Orlando Diaz


Orlando did an excellent job, and worked through challenges faced by retired clients. He responded to my questions even when he was out of town. I felt confident and reassured throughout the process and I strongly recommend him to family and friends.
Jul 11, 2018

Lynn Trinh recommends Aisling Ferguson

My husband and I are beyond happy to have worked with Aisling during our house hunting journey. She's incredibly knowledgeable, responsive and a fantastic problem solver. When there were hiccups along the way, Aisling presented us solutions and help guide us to make informed decisions. We got pre-approved and closed on our house within 8 weeks which to me and my husband, is wildly fast since we are first time homeowners.
Jul 9, 2018

Eduardo campos recommends Alberto R Zamudio

Alberto has been working with my family for quite some time now. He made sure We had the best rates compared to other lenders which was a great help! He made the whole process so easy!! Answered every question I had and always explained everything in detail. I would definitely recommend him to anyone looking to buy a home. He is a great genuine guy, which only interest is to make the whole buying process the least stressful for you. Thank you Alberto for your help!!! Looking forward to work with you in the near future.
Jul 6, 2018

Richard Malott recommends Orlando Diaz

Site Manager

Orlando was able to help us refinance our home under trying circumstances. He was always available for us. I would highly recommend Orlando to anyone looking for help with their refinance.
Jul 4, 2018

Mylene Ardanas recommends Alberto R Zamudio

Accounts Payable Analyst

Working with Alberto R Zamudio was pleasant. Alberto was professional, courteous, patient and thorough answering all our questions. He kept the ball rolling and he kept his promise. We able to closed the escrow within less than 30 days and meet our deadline to our move out date from previous location. An excellent job!!!! I would definitely highly recommend him to all our friends and colleague.
Jul 4, 2018

Chad Zahorchak & Jennifer Kellogg recommends Aisling Ferguson

Executive Integrated Producer

Aisling comes through again! This was our third purchase with her and it only gets better. Very clear and upfront with options to consider that eased our minds from day one. Very fast and thorough, highly recommend.
Jul 2, 2018

Sandy Gandolfo recommends Orlando Diaz


Orlando did a great job for our buyers, everything was easy start to finish!
Jun 26, 2018

Bill Wright recommends James W. Argo


Jim Argo is an experienced professional who can get the job done. He listened to my complicated and unorthodox financing needs and then he and his team figured out how to get those needs met. At the end of the day, that's really what matters. I would also like to commend the thoroughness and professionalism of his team which is critically important in getting lenders to fund a transaction in a highly regulated environment. Good job everyone !
Jun 26, 2018

Hugh Graham recommends Orlando Diaz

Orlando is professional, creative, and intrepid -- thanks to his tireless efforts I succeeded in securing and closing on a challenging refi. I could not have done it without him!
Jun 26, 2018

Patricia M Dolan recommends Orlando Diaz

home buyer

I had a very good experience with Orlando Diaz (San Francisco office) in Aug 2015 when I bought a home in Oakmont outside Santa Rosa. He took over from another excellent agent, John Manley, in working with me after John had a medical leave. It was a tough , stressful, and draining process to find a home to buy as I am an older, single, disabled woman, who had little experience with real estate agents at that time. To say I was naive and overly trusting is an understatement. As a result, I had two bad experiences with a couple of untrustworthy real estate agents before finding the right one with Orlando (and John's ) encouragement on the third try. Orlando was understanding, kind, patient, honest, not pushy, and walked me through the mortgage process. He found me a good mortgage with a very competitive rate. It was actually the best rate available to me, according to the son of a close friend, who has written mortgages for major banks for decades, and who kindly reviewed the mortgage that Guaranteed/Orlando found for me.
Jun 23, 2018

Dean Frick recommends Kathy Derangi

If I could give her 10 gold stars, I would!
Jun 15, 2018

Karla Ramirez recommends Alberto R Zamudio

Store manager

Alberto helped me so much with my Refi process. He answered all of my questions and explained in detail something I didn’t understand. He is very professional and I would highly recommended him.
Jun 12, 2018

David Falconer recommends Ming Leong

Owner Falcon Properties

Ming has provided financing for my commercial and residetial properties for some 15 years. Dispite some significant barriers, like interest-only loans, he has always found a lender willing to finance my properties at attractive terms and conditions. Ming knows both what's possible and impossible in the lending market. And, he knows how to get the paperwork completed and loans in place.
Jun 9, 2018

Roey Rahmil recommends James W. Argo

First-time homebuyer

James was fantastic to work with. He and his team ensured that the transaction closed smoothly on a fast timeline. He was responsive, knowledgeable, diplomatic with the other side of the deal, and unfailingly honest with me. I recommend James wholeheartedly.

Our Team

  • Aisling Ferguson

    NMLS #280915 Loan Consultant - San Francisco
    NMLS #280915 / 1850 - CA BRE #01225420 / 01215943

  • Debra Stedt

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #247657 / 1850 - CA BRE #00972315 / 01215943

  • Orlando Diaz

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #238849 / 1850 - CA BRE #01475255 / 01215943

  • Foster Weeks

    Loan Originator - San Francisco - Montgomery St.
    NMLS #253370 / 1850 - CA BRE #01383598 / 01215943

  • Kathy Derangi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #1151839 / 1850

  • Natasha Lovas

    Senior Mortgage Advisor - San Francisco - Montgomery St.
    NMLS #239455 / 1850 - CA BRE #01161948 / 01215943

  • James W. Argo

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #257031 / 1850 - CA BRE #00869591 / 01215943

  • Larry Horowitz

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #239001 / 1850 - CA BRE #01003870 / 01215943

  • Robin Patronik

    Senior Loan Officer - San Francisco - Montgomery St.
    NMLS #241087 / 1850 - CA BRE #01347330 / 01215943

  • Allan McAllister

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280540 / 1850 - CA BRE #01372084 / 01215943

  • Ken Dean

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #237940 / 1850 - CA BRE #0902556 / 01215943

  • Cecelia Tyeskey

    Sr. Mortgage Loan Consultant - San Francisco - Montgomery St
    NMLS #239861 / 1850 - CA BRE #01212004 / 01215943

  • Kevin Casey

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #238192 / 1850 - CA BRE #01178612 / 01215943

  • Alberto R Zamudio

    Sr. Loan Advisor - San Francisco - Montgomery St.
    NMLS # 282940 / 1850 - APMC CA BRE #01215943

  • Risa J. Meyer

    Mortgage Specialist - San Francisco - Montgomery St.
    NMLS #332214 / 1850 - CA BRE #01126851 / 01215943

  • Ming Leong

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 252471 / 1850 - CA BRE #01369831 / 01215943

  • Bob Siefert

    Senior Vice President - San Francisco - Montgomery St.
    NMLS #55105 / 1850 - CA BRE #00921214 / 01215943

  • Mireille Costandi

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #249322 / 1850 - CA BRE #01132350 / 01215943

  • Amy Lai

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #341535 / 1850 - CA BRE #01795977 / 01215943

  • Paul Rea

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #280163 / 1850 - CA BRE #00856755 / 01215943

  • KC Murphy

    Sr. Loan Consultant - San Francisco - Montgomery St.
    NMLS #255492 / 1850 - CA BRE #1007053 / 01215943

  • Sally Adam

    Loan Consultant - San Francisco - Montgomery St.
    NMLS #245703 / 1850 - CA BRE #01244582 / 01215943

  • Sheila Wood

    Manager/Loan Consultant - San Francisco - Montgomery St.
    NMLS #253742 / 1850 - CA BRE #00824166 / 01215943

  • Fe David

    Loan Consultant - San Francisco - Montgomery St.
    NMLS # 482592 / 1850 - APMC CA BRE #01215943