This beautiful coastal home offers the perfect blend of charm, space, and unbeatable location--west of the 5 freeway and just steps from the Pacific Ocean in the heart of Carlsbad. The single-story residence features 4 bedrooms and 2 full bathrooms, including a private en-suite bathroom off the primary bedroom with walk in closet. A large, light-filled living room provides an inviting space to relax or entertain, while updated vinyl windows enhance comfort and energy efficiency. One bedroom features a private entrance.The generous backyard offers endless potential for outdoor living, gardening, or expansion, and the detached garage includes extra storage and additional parking. In addition to its livability, this property presents an exceptional opportunity for investment or development. Situated on a spacious lot in one of Carlsbad's most desirable coastal neighborhoods, it's ideal for building multi-unit residences, luxury vacation rentals, or a custom dream home. Multi-unit potential (buyer to verify with the city), this is a rare find in a high-demand, appreciating area. Enjoy walkable access to Carlsbad's beautiful beaches, Carlsbad Village, boutique shopping, top-rated restaurants, and excellent schools. Whether you're seeking a move-in-ready beach home, a long-term investment, or a future development site, 3904 Jefferson Street delivers outstanding value in a premier coastal location.