Ten years of service and commitment.
Hundreds of satisfied owners.
Thousands of happy tenants.

CoSine Property Management is a San Diego based property management firm that provides comprehensive, professional property management.

We are committed to enhancing asset value and providing our clients with the information they need to fully maximize the financial potential of their rental properties.

Our services, advice and expertise are second to none, and our clients have repeatedly proven this through their continued referrals.

about us


We are so certain you’ll love working with us, we will never ask you to sign a long-term contract. If you are
ever unhappy with our services, you can cancel anytime. That is our 100% Satisfaction Guarantee.

What We Do

Specializing in Residential Property Management.

We currently manage over 300 properties with a portfolio value of over $120,000,000. Apartment Buildings, Single Family Homes, and Condos all benefit from our comprehensive platform of Management Services.  Whether you own one rental or a dozen, you will receive professional, full-service management to ensure your properties operate smoothly and increase in value.

And we do all this for the flat fee of 6%.

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Advanced Technology

Our Property Owners, and our tenants, love our online presence. Tenants can pay rent online, download leases and submit maintenance requests. Owners have 24/7 access to detailed property information, customizable property reports, invoices, and much more.

Extensive Marketing

We realize every day a unit is vacant we all lose money. We don’t get paid if your unit is empty, that’s why we make it a top priority to quickly fill all vacancies with qualified tenants. Our aggressive and efficient marketing ensures we consistently maintain below industry average vacancies rates.

Professional Leasing

We only place the best possible tenants in your property. Our thorough screening process for rental applicants has consistently kept our eviction rate very low. All prospective tenants are thoroughly vetted with comprehensive background investigations.

Multi-Family/Apartment Buildings

Every apartment investment needs an operating plan tailored around the owner’s specific investment objectives. This management plan should articulate specific strategies and tactics aimed at tracking and influencing the moving parts of your real estate investment.

Complete Maintenance

We have ongoing relationships with contractors, specialty repair companies and handymen to provide high quality, low cost work, usually within 24 hours. This relationship and purchasing power helps our clients get a better than market price for most of the work that is requested.

Full Accounting/Reporting

Our accounting is based on a complete and solid accounting system that was built for property managers. With our Owner’s Portal, you have the ability to track your properties expenses and income in real time, view invoices, and run reports from our suite of reporting choices.


We do a lot for you. From marketing and leasing, to maintenance and full general ledger accounting. In fact we do way too much to detail here. So view our Company Brochure to get all the details on our full-service, comprehensive Property Management Services. And remember – We do all this for a flat rate of 6% with no long term commitment.

Download Brochure


What People Are Saying About Us


NextHome Advantage Is Your #1 Resource for San Diego Realty

NextHome Advantage has partnered with CoSine Property Management to provide Clients and Tenants with help Buying and Selling homes and investments.

When working with a NextHome Advantage agent, tenants can benefit from discounted rent and cash back at closing. Current owners can benefit from discounted sales commissions.



We’d love to hear from you.

Email Address: info@cosinere.com

Office Phone: (619) 793-5484
Fax Number: (619) 793-5615

Office Address
6496 Weathers Place, Suite 110,
San Diego, CA 92121

Mailing Address
10606 Camino Ruiz, Suite 8-408,
San Diego, CA 92126