Background Readmission within 30 days after hospitalization for heart failure is a major public health problem. Objective To examine whether timing and type of post-discharge follow-up impacts risk of 30-day readmission in adults hospitalized for heart failure. Design Nested matched case-control study (January 1, 2006 to June 30, 2013). Setting A large, integrated healthcare delivery system in Northern California. Participants Hospitalized adults with a primary diagnosis of heart failure discharged to home without hospice care. Measurements Outpatient visits and telephone calls with cardiology and general medicine providers in non-emergency department and non-urgent care settings were counted as follow-up care. Statistical adjustments were made for differences in patient sociodemographic and clinical characteristics, acute severity of illness, hospitalization characteristics and post-discharge medication changes and laboratory testing. Results Among 11,985 eligible adults, early initial outpatient contact within 7 days after discharge was associated with lower odds of readmission (adjusted odds ratio [OR] 0.81, 95% CI: 0.70–0.94), whereas later outpatient contact between 8 and 30 days after hospital discharge was not significantly associated with readmission (adjusted OR 0.99, 95% CI: 0.82–1.19). Initial contact by telephone was associated with lower adjusted odds of 30-day readmission (adjusted OR 0.85, 95% CI 0.69–1.06) but was not statistically significant. Conclusions In adults discharged to home after hospitalization for heart failure, outpatient follow-up with a cardiology or general medicine provider within 7 days was associated with a lower chance of 30-day readmission.