Boxes of tampons are displayed in a pharmacy in New York. D.C. is lifting a tax on diapers and feminine hygeine products, (AP Photo/Mark Lennihan)

The nation’s capital is joining the movement to lift the sales taxes on diapers, tampons and other feminine hygiene products.

A spokeswoman for Mayor Muriel E. Bowser (D) said Wednesday she’ll sign legislation that supporters say ends a 5.75 percent tax that hurts women and hits working families the hardest.

But before it takes effect, the District needs to find more than $3 million a year to make up for the lost tax revenue in its $13 billion annual budget.

The next budget takes effect October 2017, meaning consumers must spend at least another year of paying taxes on diapers — both for babies and incontinent adults — and menstrual products.

An official with the D.C. Diaper Bank estimates lifting the sales tax will help low-income families purchase as many as a dozen additional diapers a month.

Opponents of taxes on feminine hygiene products note that in the District and elsewhere Viagra is tax-exempt as a medically necessary product.

“Women, babies, and persons with disabilities who need these products should not be taxed for natural bodily functions,” said Council member Anita Bonds (D-At Large), who authored the legislation.

Three states — Illinois, Connecticut and New York — repealed tampon taxes this year, joining five other states including Maryland. Another six states don’t tax diapers.

California Gov. Jerry Brown (D) rejected legislation that would erase taxes for both diapers and menstrual products, and a similar bill failed this year in Virginia.