This document summarizes data on the average age of principal investigators (PIs) receiving NIH research grants. The average age of all PIs receiving R01 equivalent grants has increased slightly from 2002 to 2007, rising from 51.0 to 53.0 years old. First-time PIs are on average younger, ranging from 37 to 42.6 years old depending on whether they have an MD, PhD, or MD-PhD degree. Age distributions show that most PIs cluster between 40-60 years old, with fewer outside this range. Definitions provided explain terms like first-time and R01 equivalent grants.

1. AVERAGE AGE OF
PRINCIPAL INVESTIGATORS
NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 1

2. TABLE OF CONTENTS
AVERAGE AGE OF PRINCIPAL INVESTIGATORS SLIDE
NUMBER
AVERAGE AGE OF R01-EQUIVALENT PRINCIPAL INVESTIGATORS 3
AGE DISTRIBUTION OF R01-EQUIVALENT PRINCIPAL INVESTIGATORS, FY 2007 4
AVERAGE AGE OF FIRST-TIME R01-EQUIVALENT PRINCIPAL INVESTIGATORS BY DEGREE 5
DEFINITIONS AND ADDITIONAL INFORMATION 6
NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 2

3. AVERAGE AGE OF R01-EQUIVALENT PRINCIPAL INVESTIGATORS
All Investigators First‐Time Investigators
53.0
51.0
49.0
47.0
Average Age
45.0
43.0
41.0
39.0
37.0
35.0
2002 2003 2004 2005 2006 2007
Fiscal Year
NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 3

4. AGE DISTRIBUTION OF R01-EQUIVALENT
PRINCIPAL INVESTIGATORS, FY 2007
All Investigators First‐Time Investigators
9%
8%
Average Age
7%
All Investigators
51.0
6%
First-Time Investigators
Percent of Total
42.6
5%
4%
3%
2%
1%
0%
28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80
Age
NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 4

5. AVERAGE AGE OF FIRST-TIME R01-EQUIVALENT PRINCIPAL
INVESTIGATORS BY DEGREE
MD PhD MD-PhD
45.0
44.0
43.0
42.0
Average Age
41.0
40.0
39.0
38.0
37.0
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Fiscal Year
NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 5

6. DEFINITIONS AND ADDITIONAL INFORMATION
TERM DEFINITION ADDITIONAL
INFORMATION
First-Time Investigator First-Time R01-Equivalent Investigators are defined as or Principal Investigators (PI) who have not New Investigators
previously competed successfully for a major NIH competing research grant award prior to Program
receiving a competing NIH R01-Equivalent (R01, R23, R29, R37) award.
First-Time Research Project Grant (RPG) Investigators are defined as PIs who have not previously
competed successfully for an NIH research project grant.
In normal usage “First-Time Investigators” may also be called “New Investigators”
R01-Equivalent Grants A subset of research project grants which Includes R01, R23, R29 and R37 activities
Research Grants Extramural awards made for Other Research Grants, Research Centers , Research Projects, and
SBIR/STTRs.
Includes the following: R, P, M, S, K, U series (excluding UC6) DP1, DP2, D42,G12.
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NIH Extramural Data Book – last update May 2008 Data provided by Division of Information Services, Reporting Branch AA 6