Source: U.S. Department of the Treasury. Internal Revenue Service  

Release: SOI Tax Stats - Historical Data Tables  

Units:  Number of Returns, Not Seasonally Adjusted

Frequency:  Annual

Deductible medical and dental expenses were limited, based on a percentage of AGI. The definition of expenses includes payments for certain long-term care insurance premiums and for the unreimbursed cost of certain long-term care of a chronically ill individual.

For additional information about the return filing requirements, see the annual reports, Statistics of Income-Individual Income Tax Returns at https://www.irs.gov/uac/soi-tax-stats-historical-data-tables.