About
Languages
English
Provider Specialty
Obstetrics & Gynecology
Areas of Care
Conditions
- History of Preterm Birth
Education
Medical School
University of Oklahoma Health Sciences
2015
Internship/Residency - Obstetrics & Gynecology
Tulane University School of Medicine
2019
Locations & Affiliations
Locations
MemorialCare Medical Group - Long Beach (Bixby Knolls)
3711 Long Beach Blvd.
Suite 700
Long Beach, CA
Office: 562-424-8422
Affiliations
Insurance
Please consult your health care provider or health plan for the most accurate information about your health plan’s coverage of a particular health care service offered at a MemorialCare facility. Learn more about our Accepted Health Plans.
Patient Reviews
4.9 out of 5
(213 Ratings)
(213 Ratings)
Nov 21, 2025
Vanessa P.
Nov 18, 2025
Staci S.
Nov 14, 2025
Roxana D.
She’s patient and listens to concerns. I feel very comfortable and trust her.
Nov 5, 2025
Anonymous
Calming experienceQuick to see me. Calm and put my worries at ease
Aug 5, 2025
Ariadna D.
Mar 13, 2025
Ashley G.
Mar 13, 2025
Nalina A.
She is very caring and informative. I feel comfortable dicussing my health concern with her.
Mar 6, 2025
Yoselin T.
She was very attentive, explained all my options as well as any side effects from medication. Was reassuring and made sure all my questions were answered.
Feb 21, 2025
Eleni P.
Dr Sullivan was so comforting, patient and informative.
Feb 20, 2025
Tatiana T.
I really appreciate Dr Sullivan for being kind, polite, informative and attentive and non judgmental while caring for me. I felt safe and all my health questions answered. I am happy to be a patient under her care.
Feb 20, 2025
Tatiana T.
I really appreciate Dr Sullivan for being kind, polite, informative and attentive and non judgmental while caring for me. I felt safe and all my health questions answered. I am happy to be a patient under her care.
Feb 17, 2025
Margaret R.
The ladies at the front desk were super nice and helpful. Dr SUllivan was great and took her time explaining.
Feb 12, 2025
Lesley J.
She took the time to fully understand my situation, asked all the right questions, and made decisions based on all the information
Feb 5, 2025
Amanda C.
Doctor listened to my concerns, gave helpful feedback and provided professional care & guidance.
Feb 5, 2025
Yvonne P.
Feb 2, 2025
Mary J.
Feb 1, 2025
Mary T.
Jan 24, 2025
Elsa L.
She takes her time to listen to my concerns and questions, and takes the time to explain all of my questions.
Jan 23, 2025
Alyson M.
Great experience with Dr. Sullivan - it was super efficient.
Jan 23, 2025
Diana G.
Dr. Sullivan, is always attentive, caring and very thorough in her interactions.She is definitely an asset in your team :)
Jan 17, 2025
Nia B.
Jan 10, 2025
Gliseth C.
She solved all my questions. She was kind with us.
Jan 8, 2025
Debra V.
Jan 7, 2025
Abigahil T.
Jan 6, 2025
Grace L.
Everyone here the office is extremely friendly and the office is clean!
Jan 1, 2025
Veronica I.
Dec 30, 2024
Lana M.
Quick! In and out!
Dec 17, 2024
Andrea S.
Her bedside manner. Explained all info, answered my questions. I felt my health mattered, like a very important patient! I love her!
Dec 13, 2024
Jillian W.
She's down to earth and very understanding. She doesn't mind answering questions, and is always thorough in her explanations. In addition, she respects your thoughts and listens, without being dismissive of your concerns. I trust her with my health more than most!
Nov 19, 2024
Abigail S.
Oct 31, 2024
Adriana C.
Dr. Sullivan listened to me.
Oct 18, 2024
Elizabeth C.
Oct 9, 2024
Peggy B.
Oct 8, 2024
VM
OBGYN visitListened to me, took time to educate, assisted with referrals, efficient, great bedside manner, calming, knowledgeable
Oct 3, 2024
Marlene C.
I really like Cassidy Sullivan as my OB/GYN, she is really sweet answers. All your questions keeps it very professional, but very friendly and can keep up a good conversation. I would say for anyone looking for OB/GYN I would recommend Cassidy Sullivan.
Sep 30, 2024
Ebonee M.
Sep 19, 2024
Ofie H.
Sep 19, 2024
Natalie G.
Sep 11, 2024
Jayzel P.
Sep 10, 2024
sandii 1.
Aug 27, 2024
Angelica W.
Office staff is so sweet and no matter what Dr I see they are caring, understanding and very informative.
Aug 19, 2024
Eileen R.
Aug 15, 2024
Alejandra B.
Aug 14, 2024
Misaki C.
She was great on time and kind
Aug 12, 2024
Stacey S.
Frist time for a zoom
Aug 8, 2024
Melissa A.
Very educated and great listen
Jul 30, 2024
Whitney R.
much better experience this time, thank you!
Jul 25, 2024
Nancy C.
Jul 25, 2024
Nancy C.
Jul 8, 2024
Krissia P.
Jul 8, 2024
Mireya R.
Loved the girlies they were awesome. My first time being there.
Jun 27, 2024
Tara G.
Quick, professional and helpful
Jun 12, 2024
Mallory K.
Jun 12, 2024
Yadira G.
Jun 7, 2024
Shawhena L.
Great bedside manner and explained everything well.
Jun 6, 2024
Kja H.
May 23, 2024
Jessica R.
May 15, 2024
Ari S.
She is absolutely amazing and answers all questions happily.
May 13, 2024
Cynthia R.
Staff were Professional, knowledgeable and friendly. I was made to feel comfortable
May 10, 2024
Heather C.
Everything! Great doctors who made me feel comfortable and valued. Keep up the good work! Thank you!
May 10, 2024
Kirsten H.
She is personable, caring and considerate of patient needs. I’ve seen her twice and each time she was reassuring and validated my concerns about my health. She is great at her job!
May 6, 2024
Irene M.
Very professional she explained things to me and she shows she cares
Apr 30, 2024
Chanry S.
Dr. Sullivan was very caring, was very honest with me, provided me her honest recommendation and gave me other options. The staffs there are very nice and attentive. The whole experience today was great. I walked out with positive mindset and more information than I expected from my last visit. I would like to have her again for my next visit.
Apr 30, 2024
Elyse J.
Dr Sullivan is friendly and knowledgeable. She takes the time to answer all of my questions. I would recommend her to anyone
Apr 29, 2024
Elyse M.
Dr Sullivan is friendly and knowledgeable. She takes the time to answer all of my questions. I would recommend her to any of my friends
Apr 29, 2024
Chanry S.
She was very caring, was very honest with me, provided me her honest recommendation and gave me other options. The staffs there are very nice and attentive. The whole experience today was great. I walked out with positive mindset and more information than I expected from my last visit.
Apr 18, 2024
Yuliana M.
She made me feel comfortable. She answered all my questions and addressed my concerns. She offered solutions to my concerns as well.
Apr 8, 2024
Esther W.
Been going to her for years, and she is always so compassionate and kind. Very personable, patient, and knowledgeable. I always feel comfortable seeing her, and I would recommend her highly.
Apr 3, 2024
Lindsay Z.
Dr Sullivan made me feel comfortable, listened to, and heard.
Apr 3, 2024
Nicole P.
Apr 2, 2024
Jade H.
Apr 1, 2024
Rebecca G.
Doctor was very kind and explained what was going to happened. I felt calm and comfortable with the doctor.
Mar 26, 2024
Ambrie C.
Mar 22, 2024
Hannalei P.
She made me feel comfortable and made sure that she explained and answered all my questions.
Mar 22, 2024
Ann M.
Very understandable . Really nice to me . Treated me with the most respect. Very gentle with me .. very great DR... The nurses were great and Nice .. I recommend this place.... A great caring team.
Mar 21, 2024
Eileen R.
Dr Cassidy is so calmed, knowledgeable, easy to talk to. She also asks questions and gives a lot of feedback. I visited three gynecologists before, she is the best. I’m very glad to have found her.
Mar 20, 2024
Yu C.
Mar 20, 2024
Preciosa V.
Mar 20, 2024
Sonia C.
Mar 20, 2024
Maria C.
Doctor made me feel comfortable and she was professional Also clinic staff were professional
Mar 4, 2024
maria t.
Mar 4, 2024
Ana Z.
Dr. Sullivan was very kind. What stood put most to me was how personable she was and was concerned for how I was doing and opened up the floor to any questions or things I wanted to talk through which was super helpful especially going through pregnancy for the first time. She was able to answer all my questions.
Mar 4, 2024
Maria T.
Mar 2, 2024
Cindy C.
She’s very thorough and takes her time. She answers all my questions. And super friendly and easy going.
Mar 1, 2024
Araceli S.
Feb 29, 2024
Vanessa P.
Dr. Sullivan was very caring and helpful.
Feb 29, 2024
Emi A.
She listened and offered solutions.
Feb 29, 2024
Elizabeth M.
Very attentive and courteous, she addressed our inquiries and actively sought additional questions. She possessed a serene demeanor and was very comforting, particularly during discussions pertaining to surgical procedures such as c-sections.
Feb 28, 2024
Deandralei T.
Feb 19, 2024
Lana M.
Staff and doctor very pleasant. Dr Sullivan was very thorough and sensitive.
Feb 19, 2024
Brittany S.
Feb 16, 2024
Veronica E.
Feb 15, 2024
Milette F.
She is very calm and knowledgeable
Feb 15, 2024
Milette P.
Feb 1, 2024
Teresa M.
Jan 31, 2024
Yaeleen H.
She communicated everything with detail. She talked me through the process. I’m definitely reccommending people to come see her.
Jan 31, 2024
Lisa R.
Jan 22, 2024
Amira R.
Dr Sullivan, listened to all my concerns, she’s never in a rush, always takes her time while in the room.
Jan 11, 2024
Jessica R.
Jan 10, 2024
Cassandra F.
She is very personable. Listens and is proactive.
Jan 10, 2024
Stephanie H.
Dr Sullivan is thorough and takes time to answer questions and makes great suggestions.
Jan 9, 2024
Gladys P.
Jan 9, 2024
Dorina P.
Jan 5, 2024
Tara T.
Jan 5, 2024
Anali F.
Jan 4, 2024
Genesis C.
I like that Dr. Sullivan took her time during my assessment, and provided patient education about my ultrasound results.
Jan 4, 2024
Romanita W.
Makes you feel your time is very important and takes her time to ask questions of any other concerns that need to be addressed. The staff is also very helpful and welcoming. Thanks for your time and great care.
Jan 4, 2024
Natalia O.
She was very welcoming, answered the few questions I had and just was amazing over all.
Dec 27, 2023
Orestine C.
She was purely professional kind and advise to see some who could help me with my problem
Dec 7, 2023
Marquel A.
Dec 7, 2023
Ckyla G.
Very nice informative
Dec 7, 2023
Stephanie B.
Quick, attentive, friendly service
Dec 6, 2023
Chandra
Dr. Sullivan is a caring & knowledgeable physicianThe Staff is very friendly and professional. Dr. Sullivan is caring, gentle, professional and explains things clearly and precisely so you have a clear understanding of everything. Dr. Sullivan also listens and makes time for you to ask questions. I also appreciate the fact that the office is clean, well organized and nicely decorated.
Dec 6, 2023
Julieta M.
Very nice and quick
Dec 6, 2023
Nicole T.
Cassie was very kind and personable. I felt very comfortable with her right away
Dec 5, 2023
Jill S.
Dec 5, 2023
Chandra H.
The Staff is very friendly and professional. Dr. Sullivan is caring, gentle, professional and explains things clearly and precisely so you have a clear understanding of everything. Dr. Sullivan also listens and makes time for you to ask questions.
I also appreciate the fact that the office is clean, well organized and nicely decorated.
Nov 29, 2023
Jamilyn F.
She answered all my questions
Nov 27, 2023
Elsa L.
She really listens to what I have to say and takes her time to explain everything. It’s so hard to find a good doctor that actually listens and I’m grateful I found a great OBGYN.
Nov 20, 2023
Veronica L.
Dr Sullivan has always been very professional, polite, and informative every time I’ve seen her. She explains everything she’s doing, and always answers my questions clearly and in a way I will understand. I’ve been going to her for years and will continue to do so.
Nov 17, 2023
Araceli S.
Nov 15, 2023
Fabiola M.
Made me feel very comfortable, answered all my questions
Nov 8, 2023
Kellie L.
She’s the best GYN I’ve ever seen. Thorough, knowledgeable, skilled…and seems like she actually cares.
Nov 8, 2023
Brittany S.
Dr. Sullivan is kind, knowledgeable, and thorough.
Nov 8, 2023
Fabiola M.
Nov 6, 2023
Kelly M.
She is fast, thorough, a good listener, concise communicator, intelligent and cool.
Nov 2, 2023
Kathryn R.
Nov 1, 2023
Fatima M.
The doctor was kind and easy to talk and discuss about my health.
Oct 25, 2023
Michelle M.
Oct 24, 2023
Lynette G.
One on one experience, attentive,
Oct 20, 2023
Dora S.
Dr. Sullivan explains the process when she is examining me
Therefore she has gained my trust professionally.
Oct 19, 2023
Marilyn R.
I Loved my annual "well" check with Dr. Sullivan and staff. The office and staff were organized, and friendly. checked in and was seen right away. Dr. Sullivan was friendly, knowlegable, asked questions to get to know me and spent several minutes listening and answering my questions. She had great customer service and did not rush me in and out, or spend more time with computer rather than the patient like most doctors do these days. At the end of my visit she asked if i had any other questions or concerns again allowing plenty extra time. Then she took care of follow up orders for procedure and meds before i even left the exam room. Dr. Sullivan is a joy to have as a Doctor, i highly recommend her and her staff!
Oct 19, 2023
Katherine C.
She knew the heart beat was important to me and made sure to show it to me and measure it clearly so I understood it was there and healthy!
Oct 13, 2023
Emma R.
Such kind staff, Cassidy was awesome — quick examine, talked through every step so I always knew what was going on. Best well women exam I’ve ever had!
Oct 13, 2023
Maria F.
She is very understanding of your concerns
Oct 12, 2023
Teresa M.
Oct 9, 2023
Seblua A.
Oct 6, 2023
Diana M.
I just recently moved to Long Beach and have been slowly researching new doctors. It seems so many Doctors are booked 5 or 6 months in advance - it's been frustrating to say the least. Not with Dr. Sullivan. I've been to her office three times now, once for my annual, once for an ultra sound, and then a follow up. She took the time to listen to my concerns and she answered my questions in a way I could understand. She's thoughtful, friendly, and understanding. At no time did I feel rushed in any way. And her office is so comfortable - big comfy chairs in the lobby (not your standard medical waiting room chairs), her staff is friendly, and I've never waited more than 5 minutes... even when I arrived 20 minutes early. I love that I can check in online, upload my medications, prior labs, anything and everything before the appointment. I appreciate the reminders AND the complimentary valet parking. All in all, a very comfortable, thorough, and informative office and staff. It's not easy finding new physicians. I am truly impressed with, and grateful for, Dr. Sullivan.
Oct 6, 2023
Seblua A.
throughly Explanation, postive advice
Oct 6, 2023
Mavel C.
I can say she answer all my questions
Oct 6, 2023
Mavel C.
I always have had a good experience at this clinic.
Oct 3, 2023
Allison F.
Sep 28, 2023
Lane D.
Cassidy Sullivan listened to my needs and made appropriate referrals. Easy, comfortable and professional wellness check. Friendly support staff and on time appointment!
.
Sep 28, 2023
Andrea S.
Wow! This was the best obgyn appt I have ever had and who says that about obgyn!
Sep 27, 2023
Olimpia M.
Sep 20, 2023
Courtney K.
Sep 19, 2023
Barbara H.
Dr. Sullivan is very caring and personal. She takes the time to listen and answer all your questions.
Sep 19, 2023
Joahnna A.
She was great! Claudia was great too.
Sep 19, 2023
Barbara H.
Dr. Sullivan is very caring and personal. She takes the time to listen and answer all your questions.
Sep 12, 2023
Thalia D.
Dr Sullivan takes the time to go over my concerns/questions in a thorough and relaxed manner, doesn't feel rushed.
Sep 12, 2023
Norma E.
The staff and Doctor Sullivan are very friendly and professional. I like going there. 😊
Sep 5, 2023
Stephanie D.
Dr. Sullivan and the staff are amazing and answered all of my questions.
Sep 5, 2023
Stephanie S.
Sep 1, 2023
Yolanda H.
Very professional and thorough.
Aug 30, 2023
Julia P.
Aug 23, 2023
Elizabeth G.
The doctor and staff were very helpful and friendly
Aug 23, 2023
Narissa C.
Doctor was very welcoming & answered all my questions. Very polite & informative.
Aug 11, 2023
Stephanie A.
Very Patient DoctorDr. Sullivan is very patient and easy to talk to. She's thorough and will always allow you to ask any and all questions before the appointment ends. I recommend her and her services.
Aug 9, 2023
Cristina R.
Jul 31, 2023
Alexandra K.
She is patient and listens.
Jul 17, 2023
Cassie F.
ExcellentDr. Sullivan takes time to really get to know her patients. She listens and makes you feel comfortable.
Jul 13, 2023
Brittany D.
Dr. Sullivan made me feel very comfortable and was open to all the questions I had. I didn’t feel like I was overbearing and she answered each question in a straight forward compassionate way. I felt very comfortable and heard leaving my appointment.
Jul 13, 2023
Brittany D.
Dr. Sullivan made me feel very comfortable and was open to all the questions I had. I didn’t feel like I was overbearing and she answered each question in a straight forward compassionate way. I felt very comfortable and heard leaving my appointment.
Jul 12, 2023
Diane M.
Dr. Cassidy will promptly schedule a new patient with a health issue.
Jul 11, 2023
Jessica V.
Very quick and easy!
Jul 11, 2023
Kathryn R.
Jul 6, 2023
Jazellerae Q.
Dr. Sullivan took the time to explain all of my available contraceptive options and answered my questions. I appreciate her time and care!
Jun 26, 2023
Tracye S.
Dr Cassidy Sullivan, is amazing informative, knowledgeable, compassionate and much more. Absolutely love her, easy to talk with, absolutely the best ever…
Jun 26, 2023
Tracye S.
Best OBGYN DrDr Sullivan, is informative, compassionate and the most amazing Dr ever. The office is always clean, it’s a warm and comfortable environment. They treat you like you matter as opposed to a number… Amazing
Jun 19, 2023
Eleanor C.
Dr. Sullivan always take the time to explain the treatment and the side effects of medicine that helps me decide on which treatment to take.
Jun 19, 2023
Crystal W.
Dr. Sullivan was very personable & down to earth yet extremely compassionate & thorough. This is my first pregnancy & I’m AMA, so I had a lot of questions. She did a fantastic job of listening & answering all of my questions & concerns.
Jun 3, 2023
Katherine D.
I was seen in a very timely fashion, everyone was kind and welcoming and Dr. Sullivan was so nice and super informative. She took the time to answer any and all questions.
May 11, 2023
Elsa S.
The friendliness of everyone.
The doctor took her time and I didn’t feel rush.
May 9, 2023
Colleen C.
May 8, 2023
Rylie C.
Apr 21, 2023
Raluca L.
Friendly, professional and warm
Apr 20, 2023
Irma L.
Dr Sullivan is wonderful! She explains things thoroughly, takes her time answering any concerns I have, and is present in every appointment I've had with her.
Apr 18, 2023
Brittany B.
Apr 13, 2023
Lindsey B.
She was warm and welcoming and positive
Apr 12, 2023
Jelena T.
Mar 29, 2023
Cassandra S.
Very kind, knowledgeable, and friendly
Mar 27, 2023
Mariam H.
Warm and understanding
Mar 27, 2023
Christine M.
She was approachable and easy to talk to. I was able to share concerns and didn’t feel like she was rushing.
Mar 24, 2023
Jacquelyn L.
Mar 24, 2023
Kenady B.
Dr. Sullivan was very thorough and made sure to fully address each and every one of our concerns.
Mar 23, 2023
Kenady B.
Dr. Sullivan was very thorough and made sure to fully address each and every one of our concerns.
Mar 21, 2023
Diana A.
All my visits have always been positive. The doctors and staff are always helpful and sincerely feel concern for the patient needs. I always leave understanding my visit and results. Thank you.
Mar 21, 2023
Diana A.
Mar 13, 2023
Claudine R.
Mar 8, 2023
Morgan E.
Dr. Sullivan wasn’t rushed and answered all my questions thoroughly. She and all other staff were very pleasant!
Mar 3, 2023
Flor D.
Mar 10, 2025
Cecile A.
Dec 16, 2024
Alison B.
She explained and listened.
Aug 13, 2024
Janean A.
Aug 8, 2024
Veronica B.
May 16, 2024
Jennifer M.
Apr 19, 2024
Peou B.
Feb 19, 2024
Nati R.
I was able to make an appointment and be seen right away.
Jan 26, 2024
Malak F.
Dec 5, 2023
Audrey P.
Nov 17, 2023
Maryanne L.
Nov 16, 2023
Paula K.
Very personable and has a plan for my care.
Oct 19, 2023
Glenda R.
Feel safe
Aug 10, 2023
Stephanie G.
Dr. Sullivan is very patient and easy to talk to. She's thorough and will always allow you to ask any and all questions before the appointment ends. I recommend her and her services.
Jul 19, 2023
Sarah W.
Apr 23, 2023
Ellistine D.
She explains or answers any questions so I can understand it.
Mar 10, 2025
Hemina L.
Efficiency
Apr 26, 2023
Regilah R.
Aug 6, 2024
Elizabeth G.
Visit was quick and informative.
Nov 27, 2023
Kylene K.
Services were good. I was just a little lost as to what to do after our visit.
Aug 7, 2023
Evelyn C.
Nothing was bad but it was my first time seeing Dr Sullivan
Nov 1, 2024
Anonymous
IUD InsertionShe somehow managed to forget to leave the strings on my IUD, seemingly the easiest task that anyone with a brain could execute correctly. So now, after 4 excruciatingly painful follow up appointments, where they dug around making me bleed- trying to get a hold on the device, I now have to get it surgically removed and will have permanent scars on my stomach. Do not trust this incompetent woman.
Mar 7, 2024
Jasmine G.
I would honestly never go back to this office again! It was quite a terrible experience for me and very unprofessional. Not to mention, everyone in the building was cold and standoffish. When I mentioned I was uncomfortable, Cassidy said, "well nobody likes being here." Cassidy was extremely dismissive of me and my health concerns, to the fact that I had to choose a completely different OB/GYN at another clinic just to receive proper care.I told her I was vegan and when I needed a prescription, she gave me something with gelatin and lactose in it... How does a doctor not know that these are animal-derived ingredients? A quick Google search will help, hon.I'm not sure if she was just having a bad day or what, but the basic responsibilities of a doctor were not even remotely met. She did not listen to my concerns about my health as a Black woman, the potential of having fibroids, nor did she schedule any follow-up testing for this. This was a complete waste of time and insurance money. NEVER again.I have since been seeing Dr. Ruthann Devera, who is SUCH a breath of fresh air! Complete 180 from my awful experience with Cassidy Sullivan. I LOVE Dr. Devera!!! 🥰FOLLOW UPIf I could give zero stars, I REALLY would! It keeps getting worse....So after my horrendous experience in 2023, I found a new doctor, got work done, paid for it in full, moved on with my life. Now I'm getting calls from a collections agency saying I have an unpaid bill from Cassidy? Impossible. I pay all medical bills within 30 days of receipt. 2 hours and 5 phone calls later, I learn apparently Cassidy never put my street address when she sent my lab work so they've been trying to reach me and couldn't. Now my creditscore is being impacted from the doctor's clerical error?!I'm calling again tomorrow to dispute because NOW it's outside the time frame to send to insurance... Really?! Every moment in contact with this office further solidifies my decision to NEVER see Cassidy Sullivan again. No doctor visit would've been better than taking time and money to go see this "doctor".
Source: Reviews are aggregated from third-party review sites such as Facebook, Google, HealthGrades, RepuGen, Vitals, WebMD, and Yelp.