American Journal of Respiratory and Critical Care Medicine

To the Editor:

The number of intensive care unit (ICU) beds, and the incidence of mechanical ventilation are both increasing in the United States (1, 2). Workforce projections from 15 years ago suggested an increasing shortage of critical care specialists to meet the required demands (3). To determine actual workforce trends for delivery of critical care services we examined the total Medicare billing and reimbursement and the distribution of the primary specialty of physicians receiving reimbursement for critical care medicine (CCM) services in 2008 and compared these results with previously published data on reimbursement from 1998 (4). Some of the results of this study have been previously reported in the form of an abstract (5).


We conducted a study of Medicare data from 2008 using the 5% sample from the Standard Analytic Carrier File that includes de-identified data for a random 5% sample of Medicare beneficiaries greater than 64 years of age. Medicare is a federal healthcare program for Americans 65 years or older, or who are younger with specific disabilities or end stage renal disease. It is the primary method of health insurance for individuals over age 65, covering an estimated 40 million Americans in this age group. The data included all individual critical care bills and dollars reimbursed for each critical care bill for all hospitalizations (billing codes 99291 and 99292) in 2008, as well as information on the primary specialty of the individual provider receiving reimbursement for services as designated by the Medicare Specialty Code. It is notable that any physician can bill CCM time in any location in the hospital. Therefore, we refer to delivery of critical care services, which may have occurred outside of an ICU. The outcomes of interest were the distribution of the total bills and reimbursement for critical care services across primary specialties (multiplied by 20 for national estimates), and the total dollars reimbursed for each specialty for critical care services in 2008. We then compared the data on reimbursement from 2008 with previously published data taken from 100% of Medicare billing from 1998, using an inflation calculator to account for changes in prices from 1998 to 2008 (6).


In 2008, Medicare providers generated 3.5 million bills for critical care services, with reimbursement of approximately $550 million (Table 1). Pulmonary medicine practitioners (22.7%) and intensivists (7.5%) combined accounted for almost a third of reimbursement for critical care services. Another fifth of the critical care reimbursement (21.8%) went to emergency medicine physicians. In 10 years the total Medicare reimbursement for critical care services increased by 17% ($81 million). Total reimbursement for general surgeons, intensivists, emergency medicine physicians, and pulmonologists all increased (Figure 1). The absolute increase in reimbursement for critical care services reached almost $100 million for emergency medicine physicians, and the decrease was greatest for cardiologists (Figure 1).


 Total Dollars ReimbursedTotal Bills
SpecialtyNational Estimate (Millions)*PercentageNational Estimate (Millions)PercentageNumber (1,000s)Percentage
Internal medicine$148.731.7$138.725.2854.924.7
Pulmonary medicine$93.820.0$124.722.7772.922.3
Emergency medicine$30.66.5$120.021.8785.522.7
Critical care (intensivists)$20.74.4$41.47.5260.17.5
Family practice$26.85.7$23.84.3148.94.3
General surgery$12.42.7$15.92.9101.72.9
General practice$12.62.7$10.70.827.90.8
Total (10 specialties)N/AN/A$519.693.23,228.693.3
Total (all)$468.7100.0$549.8100.03,461.9100.0

Data is on the basis of billing codes 99291 and 99292 for Medicare population ≥ 65 years with Part A and Part B coverage. Data for 2008 were multiplied by 20 to create national estimates.

*Accounting for inflation for comparison with 2008 data.


Medicare reimbursement for critical care services increased by approximately 17% over 10 years. There was a substantial shift in the distribution of providers of critical care services in the United States. In particular, in 2008, emergency medicine physicians received over a fifth of critical care billing reimbursement, and the reimbursement for self-designated intensivists and pulmonologists also increased. Billing by internists and other subspecialists within medicine, who traditionally provided much of the care in ICUs prior to the development of critical care as a separate specialty, decreased. In particular, cardiologists, who previously received a tenth of critical care billing reimbursement, appear to have a smaller role in the care of critically ill patients. Possible explanations for this change in billing reimbursement for cardiologists include a shift toward intensivist coverage of patients in coronary care units, but may also be related to the decrease in total coronary care unit beds (1).

The increased billing and reimbursement by emergency medicine physicians could be the result of the push within CCM to recognize and treat critical illnesses, such as severe sepsis, earlier. In particular, early-goal directed therapy emphasizes aggressive resuscitation and requires emergency medicine physicians to provide critical care services, such as insertion of a central venous catheter, in an emergency department (7). Another possibility is that changes in billing practices have allowed emergency medicine physicians to bill more fully than before for services that have always been provided in the emergency department. Although all critical care physicians face increased pressure to generate revenue, recent data suggest that emergency departments in particular may be improperly coding bills for payment due to the ease of “upbilling” with electronic health records (8). Finally, the demographics of the physician workforce have changed, and during this time period there has been a substantial increase in the number of physicians trained and certified in emergency medicine (9).

This study was limited to people with Medicare over age 65, and the billing patterns may not be the same for younger patients. Second, these data do not provide information regarding the location of the patient when the bill was generated, so it remains unclear how much emergency medicine physicians are involved in care of patients in the ICU versus the emergency department. Our data on billing were also not linked directly with patient encounters, so we cannot comment on the billing patterns associated with different types of patients, hospitals or regions of care.

These data only reflect the use of critical care codes, and therefore do not include reimbursement for procedures performed in the ICU (i.e., intubation, central line placement) or for providers billing evaluation and management codes. We also could not determine whether physicians with a different primary specialty may also be board-certified intensivists. However, a provider is required to designate their primary specialty on application to the Center for Medicare and Medicaid Services for reimbursement. It is only in the past year that emergency medicine physicians have been eligible for certification in CCM, suggesting that the majority of these physicians are unlikely to be dual certified.

The delivery of critical care is clearly shifting, with new emphasis on diagnosis and treatment in the emergency department and the use of rapid response teams for early diagnosis on the wards (10). The role of self-designated intensivists is also increasing. These data provide important information regarding how the healthcare system is adapting to demands for critical care services, and highlight groups to target for further education and training in CCM to ensure appropriate high quality care in the future.

1. Halpern NA, Pastores SM. Critical care medicine in the United States 2000-2005: an analysis of bed numbers, occupancy rates, payer mix, and costs. Crit Care Med 2010;38:6571.
2. Carson SS, Cox CE, Holmes GM, Howard A, Carey TS. The changing epidemiology of mechanical ventilation: a population-based study. J Intensive Care Med 2006;21:173182.
3. Angus DC, Kelley MA, Schmitz RJ, White A, Popovich J Jr; Committee on Manpower for Pulmonary and Critical Care Societies (COMPACCS). Caring for the critically ill patient. Current and projected workforce requirements for care of the critically ill and patients with pulmonary disease: can we meet the requirements of an aging population? JAMA 2000;284:27622770.
4. Medicare reimbursement for critical care services. Office of Inspector General; Department of Health & Human Services, 2001.
5. Evans AS, Brady J, Sladen RN, Wunsch H. Ten year trends in specialist billing for critical care services in the United States (1998). Am Soc Anesthesiol 2007;2011:A098.
6. United States Department of Labor. Inflation calculator [accessed 2012 Mar 30]. Available from:
7. Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, Peterson E, Tomlanovich M; Early Goal-Directed Therapy Collaborative Group. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med 2001;345:13681377.
8. Pitts SR. Higher-complexity ED billing codes—sicker patients, more intensive practice, or improper payments? N Engl J Med 2012;367:24652467.
9. Center for Workforce Studies. 2008 physician specialty data. Washington, DC: Association of American Medical Colleges; 2008.
10. Jones DA, DeVita MA, Bellomo R. Rapid-response teams. N Engl J Med 2011;365:139146.

Author Contributions: Study concept and design: A.S.E. and H.W.; acquisition of data: H.W.; analysis and Interpretation of data: A.S.E., J.E.B., R.N.S., and H.W.; drafting of manuscript: A.S.E. and H.W.; critical revision of the manuscript for important intellectual content: A.S.E., J.E.B., R.N.S., and H.W.; statistical analysis: J.E.B. and H.W.; obtaining funding: H.W.; administrative, technical, or material support: J.E.B., R.N.S., and H.W.

Supported by Award Number K08AG038477 from the National Institute on Aging (H.W.) and the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant Number UL1 TR000040 (H.W.).

Role of the Sponsor: The funding source had no role in the design and conduct of the study, the analysis and interpretation of data, or in the preparation, review, or approval of the manuscript.

Author disclosures are available with the text of this letter at


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