http://grants.nih.gov/training/careerdevelopmentawards.htm

K awards are for individuals who have had some success with prior grant awards and publications, but still require mentorship and guidance from a more experienced investigator.  Earning a “K” award is a major milestone for up and coming emergency medicine researchers.

K01-Mentored Research Scientist Award - supports clinicians and Ph.D.s exclusively in epidemiology, modeling, and outcomes research. Duration of three to five years, not renewable. - supports more established investigators who have independent support and show a need for an intensive research focus in an NIH institutes mission. Duration of three to five years, not renewable. 

K08-Mentored Clinical Scientist Research Career Development Award - supports basic research leading to independence for M.D.s and other clinical health professionals. Duration of three to five years, not renewable. May include didactic studies.

K22-Career Transition Award (K22) - provides start-up support for postdocs making the transition to assistant professors at an academic institution. Two-year duration, not renewable. 

K23-Mentored Patient-Oriented Research Career Development Award - supports young clinicians who want to conduct patient-oriented research. Five-year duration, not renewable. 

K24-Midcareer Investigator in Patient-Oriented Research - supports mid-career scientists who are already conducting patient-oriented research and would like to spend more time mentoring young clinicians interested in that area. Duration of three to five years (minimum of three), renewable. 

K99/R00-NIH Pathway to Independence Award - NIH Institutes (selected) supports salary and research expenses for one year in the mentored K99 phase. The R00 phase provides two years of support to continue the research project independently. There are very few awards, not renewable.

K12 - awarded to institutions for research fellowships