Dr. Kleinhenz is a Professor of Medicine in the UCSF Department of Medicine, Division of Pulmonary, Critical Care, Allergy-Immunology and Sleep Medicine. She is the Director of the UCSF Adult Cystic Fibrosis Program and Associate Director of the UCSF Cystic Fibrosis Center. Dr. Kleinhenz is also a Transplant Physician of the UCSF Lung Transplant Program.

Dr. Kleinhenz's clinical interests include adult cystic fibrosis, bronchiectasis due to conditions other than cystic fibrosis, pulmonary disease from non-tuberculous mycobacteria and lung transplantation. She maintains an active consultative practice in the UCSF Pulmonary Practice at Parnassus.

Dr. Kleinhenz long-term commitment to adult cystic fibrosis care and management. She is a member of the Center Committee of the Cystic Fibrosis Foundation and participates in the Foundation's Quality Assurance Program. She has championed the training of clinicians in adult cystic fibrosis care; several of her former trainees now staff and direct Adult Cystic Fibrosis Programs across the Nation. Dr. Kleinhenz has directed several trials of potential therapies for cystic fibrosis at UCSF.