The second Wave (W2) of the National Social Life, Health, and Aging Project (NSHAP), a nationally representative, longitudinal survey of older adults now between the ages of 62 and 90, conducted approximately 3,400 interviews. Selected coresidential romantic partners as well as W1 panel nonrespondents were selected for W2. Data collection included in-person questionnaires, up to 15 biomeasures, and a post-interview questionnaire. A proxy questionnaire also collected data on respondents that were deceased or in too poor health to participate in W2. Biomeasure collection included height, weight, hip and waist circumference, blood pressure, heart rate, and preventricular contraction, timed walk and chair stands, smell, saliva collection using a Salivette (cortisol), saliva passive drool in a tube (dehydroepiandrosterone, estradiol, progesterone, testosterone), dried blood spots (Epstein-Barr virus antibody titers, C-reactive protein, glycosylated hemoglobin, hemoglobin, cholesterol, high-density lipoprotein), whole blood in a microtainer (cytokines), urine (creatinine, vasopressin, oxytocin), Oragene (genotype), respondent-administered vaginal swabs (bacterial vaginosis,yeast, and vaginal cell cytology), and Actiwatch (sleep patterns and activity). Measures, such as response and cooperation rates, are also provided to evaluate design and implementation. This article describes both innovation in the development and implementation of W2 as well as fidelity to W1 study design and data collection procedures.