Medicare enrollment grew from 20,398 thousand people in 1970 to 66,701 thousand in 2023, according to the 2024 Medicare Trustees Report. The same report shows Medicare expenditures rising from 0.71 percent of GDP in 1970 to 3.76 percent in 2023, with later figures presented as projections.
Table of contents
- Enrollment at a glance
- Medicare enrollment from 1970 to 2000
- Enrollment from 2005 to 2023
- How the Medicare components compare
- Medicare spending as a share of GDP
- Projected spending through 2098
Enrollment at a glance
The 2024 Medicare Trustees Report, Table V.B3, reports enrollment in thousands. Total Medicare enrollment was 20,398 thousand in 1970, 24,864 thousand in 1975, and 28,433 thousand in 1980. It reached 31,081 thousand in 1985, 34,251 thousand in 1990, 37,594 thousand in 1995, and 39,688 thousand in 2000.
The later historical totals were 42,606 thousand in 2005, 47,720 thousand in 2010, 55,589 thousand in 2015, 63,980 thousand in 2021, and 66,701 thousand in 2023. These are reported enrollment figures for the stated years, not a forecast series.
The component figures do not always add together as a simple sum because the report presents overlapping program categories. For that reason, total enrollment is reported separately below rather than calculated from the component rows.
Medicare enrollment from 1970 to 2000
Part A enrollment was 20,104 thousand in 1970, compared with Part B enrollment of 19,496 thousand. In 1975, the corresponding figures were 24,481 thousand for Part A and 23,744 thousand for Part B. By 1980, Part A enrollment had reached 28,002 thousand and Part B enrollment had reached 27,278 thousand.
The report also lists Medicare Part D/private health plans enrollment for later years in this historical sequence. That category was 1,271 thousand in 1985 and 2,017 thousand in 1990. It increased to 3,467 thousand in 1995 and 6,856 thousand in 2000.
The main enrollment figures for this period are shown here:
| Year | Part A enrollment (thousand) | Part B enrollment (thousand) | Total Medicare enrollment (thousand) |
|---|---|---|---|
| 1970 | 20,104 | 19,496 | 20,398 |
| 1975 | 24,481 | 23,744 | 24,864 |
| 1980 | 28,002 | 27,278 | 28,433 |
| 1985 | 30,621 | 29,869 | 31,081 |
| 1990 | 33,747 | 32,567 | 34,251 |
| 1995 | 37,175 | 35,641 | 37,594 |
| 2000 | 39,257 | 37,335 | 39,688 |
Part A enrollment was 30,621 thousand in 1985, 33,747 thousand in 1990, 37,175 thousand in 1995, and 39,257 thousand in 2000. Part B enrollment was 29,869 thousand in 1985, 32,567 thousand in 1990, 35,641 thousand in 1995, and 37,335 thousand in 2000. Each figure comes from the 2024 Medicare Trustees Report, Table V.B3.
Enrollment from 2005 to 2023
In 2005, the report recorded 42,233 thousand Part A enrollees and 39,752 thousand Part B enrollees. It separately recorded 1,841 thousand Medicare Part D enrollees and 5,794 thousand Medicare private health plans enrollees. Total Medicare enrollment was 42,606 thousand.
By 2010, Part A enrollment was 47,365 thousand and Part B enrollment was 43,882 thousand. Part D enrollment was 34,772 thousand, while Medicare private health plans enrollment was 11,693 thousand. Total Medicare enrollment was 47,720 thousand.
The 2015 figures were 55,246 thousand for Part A, 50,756 thousand for Part B, 41,786 thousand for Part D, and 17,495 thousand for Medicare private health plans. Total Medicare enrollment was 55,589 thousand.
For 2021, the report listed 63,643 thousand Part A enrollees, 58,393 thousand Part B enrollees, 49,977 thousand Part D enrollees, and 27,548 thousand Medicare private health plans enrollees. Total Medicare enrollment was 63,980 thousand.
The latest historical year included in the supplied Table V.B3 figures is 2023. Part A enrollment was 66,342 thousand, Part B enrollment was 60,832 thousand, Part D enrollment was 52,861 thousand, and Medicare private health plans enrollment was 32,165 thousand. Total Medicare enrollment was 66,701 thousand.
How the Medicare components compare
Part A and Part B remained the largest reported enrollment categories throughout the supplied historical series. Part A was 20,104 thousand in 1970 and 66,342 thousand in 2023. Part B was 19,496 thousand in 1970 and 60,832 thousand in 2023.
The report’s later categories show a separate pattern. Medicare Part D enrollment was 1,841 thousand in 2005, 34,772 thousand in 2010, 41,786 thousand in 2015, 49,977 thousand in 2021, and 52,861 thousand in 2023. Medicare private health plans enrollment was 5,794 thousand in 2005, 11,693 thousand in 2010, 17,495 thousand in 2015, 27,548 thousand in 2021, and 32,165 thousand in 2023.
These component entries describe the categories and years as presented by the trustees. The supplied source does not provide additional definitions or methodology for reconciling the categories with the total, so the figures are best read as reported rows rather than recomputed totals.
Medicare spending as a share of GDP
The 2024 Medicare Trustees Report, Table V.B2, reports Medicare expenditures as a percentage of GDP. In 1970, Medicare expenditures were 0.71 percent of GDP. The table identifies 0.51 percent for Part A expenditures and 0.21 percent for Part B expenditures in that year.
Medicare expenditures were 2.62 percent of GDP in 2005 and 3.48 percent in 2010. In 2023, the historical figure was 3.76 percent of GDP. These values measure Medicare expenditures relative to the size of the economy for the stated years.
The historical figures provide context for the forward-looking values in the same table. They should not be interpreted as household premiums, an individual’s out-of-pocket costs, or a direct measure of the benefits received by any one enrollee. They are program expenditures expressed as a share of GDP.
Projected spending through 2098
The 2024 Medicare Trustees Report labels the later Table V.B2 values as projections. Projected Medicare expenditures were 3.83 percent of GDP in 2024, 4.24 percent in 2027, and 4.64 percent in 2030. The projection was 5.09 percent of GDP in 2033 and 5.30 percent in 2035.
The sequence includes both near-term and long-range estimates. The 2024, 2027, and 2030 entries are relatively close to the last historical observation listed here, while the 2033, 2035, and 2040 entries extend the projection horizon. The later points—2050, 2065, 2070, 2080, and 2098—describe the longer range covered by the table. Each percentage belongs to its stated year, and the report does not present these figures as a monthly or annual household payment amount.
For the following years, projected Medicare expenditures were 5.65 percent of GDP in 2040, 5.86 percent in 2050, 6.12 percent in 2065, and 6.20 percent in 2070. The table projected 6.31 percent of GDP in 2080 and 6.20 percent in 2098.
| Period | Medicare expenditures as a share of GDP | Status |
|---|---|---|
| 1970 | 0.71% | Historical figure |
| 2005 | 2.62% | Historical figure |
| 2010 | 3.48% | Historical figure |
| 2023 | 3.76% | Historical figure |
| 2024 | 3.83% | Projection |
| 2030 | 4.64% | Projection |
| 2040 | 5.65% | Projection |
| 2050 | 5.86% | Projection |
| 2070 | 6.20% | Projection |
| 2098 | 6.20% | Projection |
The projected series is not a statement that any one future value is certain. It is the set of estimates presented in Table V.B2 of the 2024 Medicare Trustees Report for the listed years. Keeping the historical and projected periods separate is important when using Medicare statistics for planning, policy discussions, or comparisons over time.
All enrollment and spending figures in this article are from the 2024 Medicare Trustees Report: Table V.B3 for enrollment and Table V.B2 for expenditures as a percentage of GDP. The supplied source record identifies this information as legacy research that was not independently verified; the figures are therefore presented as reported by that named source.