I agree that you should find out as much as you can about MGUS. This will help you prepare questions for doctors when you seek a second opinion. Here are 3 websites that talk about MGUS in plain language:
- MGUS Mayo Clinic https://www.mayoclinic.org/diseases-conditions/mgus/symptoms-causes/syc-20352362
- MGUS to Myeloma: Study Suggests Risk of Progression Can Change (NCI) https://www.cancer.gov/news-events/cancer-currents-blog/2019/mgus-multiple-myeloma-progression-risk
- How Serious Is Monoclonal Gammopathy of Undetermined Significance (MGUS)? (healthline) https://www.healthline.com/health/how-serious-is-mgus

I might suggest reading them and returning here if you have questions. Fellow patients will be happy to share their experiences. And share with you questions you can ask the doctors.

Where to get a second opinion depends on a number of factors. Choose a large cancer center with expertise in hematological cancers, like Mayo Clinic. The other factors are personal. You may need to consider your insurance coverage, your financial and mobility ability to travel, or a preference to stay close to home.

@allu, About 5% of 70+ years old have MGUS and most of them have no symptoms based on a Mayo Clinic study. The majority of MGUS patients will not experience a progression to cancer. As an individual who was diagnosed with MGUS last July, I would recommend finding one good Hematologist who will run the proper testes and explain MGUS in details. It is my opinion that you don’t need a MM Spcialist if the MGUS is stable. No need to get stressed and loose sleep on a quite common blood condition.