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NASP Communiqué, Vol. 33, #6
March 2005

NASP Study: How Many School Psychologists Are There?

By Jeffrey L. Charvat,
Manager of Research and Information Services

How many school psychologists are there in the country?  How many are providing psychological services in the nation’s schools?  A 2004 NASP study examining these questions provides the best—perhaps only—recent empirically based answers.  This article briefly presents some of the results of the study, makes comparisons with the previous study in 1999, and discusses the implications of collecting this type of data for the future of the profession.  Estimates of changes in the degree to which states are meeting the NASP-recommended ratio of one school psychologist per 1,000 students are also provided, and the benefits and limitations of such estimates are considered.  

The school psychology credentialing systems come to mind first as logical sources of information on the number of school psychologists in the country.  Apart from the NASP Nationally Certified School Psychologist (NCSP) credential, the credentialing of school psychologists is a matter governed by state laws, and there is a great deal of variability from state to state.  The state agency usually charged with the credentialing of school psychologists is the state department of education, though in some states psychology licensing boards also credential school psychologists.  Twenty-six states use the NCSP as part of their standards for state certification.  The NASP website provides brief summaries by state of certification and licensure requirements, with links to state departments of education and state licensing boards (www.nasponline.org/certification/state_info_list.html). 

With these credentialing systems in place, determining the number of credentialed school psychologists in the country would seem to be an easy matter.  However, this has not proven to be the case.  Difficulties have been reported in obtaining official data on the number of credentialed school psychologists in some states.  This situation is one of several reasons why there is currently no compendium of school psychology workforce data that one can reach for to discover how the workforce changes from year to year. 

One federal publication, however, is becoming just such a centralized source for information on mental health practitioners and trainees, from social workers and psychiatrists to psychiatric nurses and school psychologists.  The most recent edition, Mental Health, United States, 2002, includes school psychology data for 2000, making possible comparisons between the school psychology workforce and the other professions that provide mental health services (Center for Mental Health Services, 2004). One impetus for the present study was the need for updated data for the 2004 edition of this publication.  The study was conducted in the fall of 2004 (Charvat, 2004). 

Study Method

A two-stage survey approach was employed in this study.  First, to represent the 50 states and the District of Columbia, a sample of 10 states was randomly selected using a stratified sampling approach based on similarities and differences in states in terms of the population of school psychologists and the residential population.  Leaders in each of the 10 school psychology state associations were asked by e-mail to provide the number of credentialed school psychologists in their state and the number of school psychologists providing services.  If their state agencies were unable to supply official statistics, leaders were asked to make estimates through the systematic application of logical assumptions about their state’s school psychology population—in short, estimating the unknown by extrapolating from the what is known (e.g., state association membership). 

All 10 states responded to the survey, and the results from the sample were compared with a similar survey carried out in 1999 (Thomas, 2000).  Analysis of the results of this first stage of the survey yielded a formula representing the overall rate of change in the number of school psychologists from 1999 to 2004.  This formula was used to extrapolate from the 1999 data the current number of credentialed school psychologists in each of the states that did not participate in the survey.  A similar process was used to estimate the number of school psychologists providing services in the remaining states. 

In the second stage of the survey, the remaining state association leaders were provided with the two estimates and notified that these figures were to be used to represent their state in the publication Mental Health, United States, 2004.  They were asked to review the estimates to determine if they accurately reflect the conditions in their state and, if not, to provide either the official statistics from their state agencies or their own estimates, if the former were not available.  They were informed that the absence of a response would be interpreted as indicating agreement that the data accurately reflect the situation in their state. 

Number of Credentialed School Psychologists

Overall, 33 states and the District of Columbia provided data for their states or approved the estimates that were sent to them.  The original estimates for the remaining 17 states were used in subsequent analyses.  The results indicate that there are 37,893 credentialed school psychologists in the 50 states and the District of Columbia.  This represents an increase of 6,615 or 21% from 31,278 in 1999 (Thomas, 2000).  The first column of Table 1 provides these results by state. 

Table 1. Estimated Number of School Psychologists by State in 2004 and Comparison of Ratios of Students to School Psychologists by State in 1999 and 2004

State 2004 Certified/Licensed School Psychologists 1 2004 School Psychologists in Public Schools 2 2004 Students per School Psychologist 3 1999 Students per School Psychologist 4 Percentage Change from 1999 to 2004
AK 165 128 1,051 1,486 -29%
AL 191 148 4,997 3,384 48%
AR 228 177 2,552 2,660 -4%
AZ 700 543 1,729 2,014 -14%
CA 4,336 3,360 1,892 2,480 -24%
CO 900 698 1,078 1,518 -29%
CT 1,375 1,066 535 844 -37%
DC 80 62 1,228 3,206 -62%
DE 112 87 1,340 1,283 4%
FL 1,652 1,280 1,984 2,407 -18%
GA 727 563 2,655 2,655 0%
HI 60 47 3,953 8,252 -52%
IA 475 368 1,310 1,500 -13%
ID 278 215 1,153 1,666 -31%
IL 2,006 1,555 1,341 1,531 -12%
IN 498 386 2,601 2,287 14%
KS 800 620 760 1,166 -35%
KY 353 274 2,415 2,129 13%
LA 390 302 2,417 2,611 -7%
MA 997 773 1,272 1,002 27%
MD 750 581 1,491 1,871 -20%
ME 274 212 962 1,355 -29%
MI 900 698 2,559 1,755 46%
MN 897 695 1,218 1,499 -19%
MO 208 161 5,735 2,373 142%
MS 80 62 7,946 3,505 127%
MT 215 167 900 1,929 -53%
NC 700 543 2,463 1,936 27%
ND 64 50 2,101 2,728 -23%
NE 375 291 982 1,522 -35%
NH 278 215 964 1,223 -21%
NJ 1,307 1,013 1,350 995 36%
NM 215 167 1,922 951 102%
NV 198 153 2,408 2,249 7%
NY 4,600 3,565 642 817 -21%
OH 1,514 1,173 1,567 1,824 -14%
OK 248 192 3,249 2,558 27%
OR 270 209 2,648 1,733 53%
PA 1,731 1,342 1,354 2,327 -42%
RI 176 136 1,167 1,330 -12%
SC 688 533 1,303 2,022 -36%
SD 92 71 1,796 3,107 -42%
TN 447 346 2,679 2,389 12%
TX 2,131 1,652 2,579 2,320 11%
UT 230 178 2,744 1,726 59%
VA 679 526 2,237 2,343 -5%
VT 124 96 1,040 1,341 -22%
WA 826 640 1,585 1,495 6%
WI 1,101 853 1,033 1,196 -14%
WV 143 111 2,549 2,714 -6%
WY 109 84 1,043 1,432 -27%
Total 37,893 29,367 1,621 1,816 -11%

Number of School Psychologists Providing Services

In estimating the number of school psychologists providing services, these survey results were supplemented with data from the latest NASP Membership Survey (Curtis, Chesno Grier, & Hunley, 2004) and the Twenty-Fourth Annual Report to Congress on the Implementation of the Individuals with Disabilities Education Act (U.S. Department of Education, 2002).  The analysis yielded an estimate of 32,322 school psychologists providing services in the country in 2004, approximately 85% of the total number of credentialed school psychologists. 

Determining the number of school psychologists providing school psychological services was a challenge for many states, given that it necessitates accounting for the full- and part-time activities of school psychologists in a variety of settings including those in public schools, private schools, independent practice, and so on.  It also requires the ability to factor out university faculty, administrators, retirees, etc., as well as accounting for those who fulfill multiple roles, such as those university faculty who provide services on a limited basis. 

The number of school psychologists providing services in public schools is estimated to be 29,367.  The second column of Table 1 presents these results by state.  These estimates were obtained by multiplying the number of credentialed school psychologists in each state by 77.5%, the percentage of school psychologists working in public schools according to the most recent NASP Membership Survey (Curtis et al., 2004). 

Ratio of Students to School Psychologists

Additional analyses suggest that there are 1,621 students per school psychologist in the United States, which represents an 11% decrease from the 1,816 reported for 1999 (Thomas, 2000).  See Table 1 for estimates by state and comparisons between 1999 and 2004.  Note that these two estimates resulted from different methods of data collection, suggesting the need for some caution in their interpretation.  The first estimate was made using findings from this study, the percentage of school psychologists in public schools from the NASP Membership Survey (Curtis et al., 2004), and the number of public school students reported by the National Center for Education Statistics (2002–03).  The second estimate is the mean of self-reported ratios from a survey of NASP members. 

Other cautions are warranted.  Note, for example, that these ratio estimates are for the entire state, whereas the NASP-recommended ratio of one school psychologist for every 1,000 students is for the “school psychological services unit” (NASP, 2000, p. 54).  Of course, if all units in the state meet the ratio, then the state ratio will reflect this fact.  However, the opposite is not necessarily true.  Because of variability between the school psychological services units, even if the recommended ratio is met by the state, it is very possible that some units within the state have not met the recommended ratio (and may even be far from meeting it).  The ratio also does not provide any information on the quality of services and perhaps only limited information on the actual workload of school psychologists. 

As can be seen from Table 1, the ratios vary dramatically between states.  This is worth noting because the amount of the ratio can influence the types of professional practices used by school psychologists (Curtis, Hunley, & Chesno Grier, 2002).  However, it is important to remember that changes in the types of professional practices used will not themselves be reflected in the ratio.  The ratio can stay the same even in the context of increases in school psychologists’ formal or informal job responsibilities, such as when the need for services among a population of students increases as a result of a crisis in the community.  Thus, it is critical to recognize that the NASP-recommended ratio is a meaningful tool for measuring and comparing the impact of school psychologists’ services only to the extent that one keeps in mind the amount and type of services school psychologists are providing.  Some suggested future directions for school psychology, such as for example doing more with less through increased indirect service delivery (Canter, 2003), may be less well served by a focus on ratios as a measure of the impact of school psychologists’ efforts.  The idea of indirect service delivery—that school psychologists need to impact more students by restructuring their roles—runs counter to the linear view of measuring impact that is a basic assumption of the ratio. 

An Alternative to Ratios?

Concerns about the meaning of the ratio are reflected in the debate about caseload versus workload (see the related article in this Communiqué).  Caseload is epitomized by the measure of the ratio of students to school psychologists and is an important administrative tool for monitoring the relationship between staff levels and the number of students that potentially need to be served.  It has the benefit of being relatively easy to measure and compare and can provide documentation of historical changes.  As such, it can be used for setting goals related to improved service delivery.  Decreasing the ratio can be used as a proxy measure for increased service provision to students, but only if one has information suggesting that the needs of the students are relatively constant, likely a risky assumption to make in some school systems. 

By contrast, workload refers to the actual amount of various types of services that a particular school psychologist or psychological services unit provides.  It can, thus, potentially present a more detailed and realistic picture of the degree to which it is reasonable for a particular practitioner to be asked to serve more students—indeed, even how reasonable it is to assume that the practitioner’s current working conditions support effective service delivery.  Its benefits notwithstanding (see related article), it has its drawbacks.  For example, determining the workload for any particular practitioner or psychological services unit is a labor-intensive task involving the daily documentation of activities.  This may be unduly burdensome for those with an already packed schedule.  And, as with any self-reported measure, it can introduce an element of measurement error because not everyone is skilled at such self-observation, because it can be an onerous task when added to an already overburdened schedule, and because of self-serving biases (aren’t we all overworked?).  In addition, its usefulness to administrators as a tool for making decisions depends upon their having workload information on each practitioner or unit.  Thus, caseload and workload approaches are perhaps most realistically viewed as complementary rather than as mutually exclusive. 

Collecting Data for the Future of School Psychology

This article touched briefly on some of the issues regarding the collection and use of school psychology data.  Conducting this study raised questions concerning how best to institutionalize the collection of school psychology’s workforce data so as to make valid and reliable information available from year to year.  Some initiatives are underway to develop improved systems of data collection for the range of professions that provide mental health services.  For example, NASP participates in the Alliance of Mental Health Professions, a workgroup of the Center for Mental Health Services of the Substance Abuse and Mental Health Services Administration (SAMHSA), which is working to develop a standardized tool for collecting mental health service provider data across professions.  School psychology’s representation among the range of mental health service professions in Mental Health, United States, 2002 is one result of that collaboration.  NASP is committed to improving—alone and in collaboration with others—the systems for collecting and using data that will support effective decision-making regarding school psychology’s role in serving America’s mental health needs in the future. 


Canter, A. (2003, October).  Recruitment or restructuring roles: A nonempirical look at the personnel shortage in school psychology. Communiqué, 32(2), 44.

Center for Mental Health Services (2004).  Mental health, United States, 2002.  Edited by R.W. Manderscheid and M.J. Henderson.  DHHS Publication No. (SMA) 3938.  Rockville, MD: Substance Abuse and Mental Health Services Administration.  Available: www.mentalhealth.org/publications/allpubs/SMA04-3938/default.asp.

Charvat, J. L. (2004). School psychologists in the U.S. in 2004: A survey of state associations. Unpublished paper. Bethesda, MD: National Association of School Psychologists.

Curtis, M. J., Chesno Grier, J. E., & Hunley, S. A. (2004).  The changing face of school psychology: Trends in data and projections for the future.  School Psychology Review, 33, 49-66. 

Curtis, M. J., Hunley, S. A., & Chesno Grier, J. E. (2002).  Relationships among professional practices and demographic characteristics of school psychologists.  School Psychology Review, 31, 30-42. 

National Association of School Psychologists (2000). Professional conduct manual for school psychologists (4th edition). Bethesda, MD: Author.

National Center for Education Statistics (2002-03).  State profiles.  In The nation’s report card [online].  Available: http://nces.ed.gov/nationsreportcard/states.

Thomas, A. (2000, April).  Report to the National Association of School Psychologists’ delegate assembly on the state demographic survey.  Bethesda, MD: National Association of School Psychologists.

U.S. Department of Education (2002). Twentieth-fourth annual report to Congress on the Individuals with Disabilities Education Act. Washington, DC: Author.


1Based on a 2004 survey of state school psychology associations (Charvat, 2004).

2Based on the 1999-2000 survey finding that 77.5% of school psychologists work in public schools (Curtis, Chesno Grier, & Hunley, 2004).

3Based on the number of public school students in the 2002-03 school year (National Center for Education Statistics, 2002-03). 

4This ratio is the mean of 1999 survey responses from a sample of NASP members, which includes responses from school psychologists in both public and private schools (Thomas, 2000).