Medicaid Became a Leading Payer for Inpatient Hospital Stays Over 15 Years, Report Finds

Allison Inserro

Medicaid became a leading payer for inpatient hospital stays among certain age groups between 2000 and 2015, a brief from the Agency for Healthcare Research and Quality (AHRQ) recently reported. AHRQ’s Healthcare Cost and Utilization Project (HCUP) Statistical Brief presents data on hospital inpatient stays from 2000 through 2015 by age group and primary payer.

It examines: This report covers the time period from before the Affordable Care Act (ACA) was enacted in 2010, including the period of Medicaid expansion by states after 2012. One of the main goals of the ACA was to significantly reduce the number of uninsured by providing more affordable coverage options through Medicaid and insurance marketplaces. 

The National Inpatient Sample from 2000 to 2015 was used to generate national estimates of inpatient stays.

The total number of inpatient stays related to maternal and neonatal diagnoses accounted for 22% to 25% of all inpatient stays, and for 34% to 46% of those stays, Medicaid was the primary expected payer. As such, due to the relative size of that subpopulation and the high concentration of Medicaid in that group, maternal and neonatal stays were excluded from the remaining analysis.

The remaining nonneonatal, nonmaternal stays were divided into 4 age groups: younger than 18 years; 18 to 44; 45 to 64; and 65 and older.

Over the 15-year period, the population rate of inpatient stays dropped for all age groups; the largest percentage decrease (25%) was among patients 65 years and older.

Across age groups, from 2000 to 2015, for patients 64 years or younger, the share of inpatient stays with an expected primary payer of private insurance decreased and the share of stays with Medicaid increased. The share of uninsured stays reached its 16-year low in 2015.

For patients aged 18 to 64 years, the share of stays with Medicare increased during the 16-year period. 

From 2007 to 2015, Medicaid was the top primary payer for patients younger than 18 years; its share exceeded 50% starting in 2012.

From 2000 to 2015, the share of Medicaid for those aged 18 to 44 years and 45 to 64 years increased by 74% and 68%, respectively.

In addition, among patients aged 18 to 44 years, inpatient stays covered by Medicare increased by 21% from 2000 to 2015. Among patients aged 45 to 64 years, the share of stays covered by Medicare increased by 43% from 2000 to 2015.

Among patients 65 years and older, Medicare and private insurance together accounted for about 97% of inpatient stays each year.


Agency for Healthcare Research and Quality. Trends in hospital inpatient stays by age and payer, 2000-2015 [HCUP statistical brief #235]. Published January 2018. Accessed February 21, 2018.
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