The taxman came for her — with a vengeance.

An East Harlem granny who runs a tiny day-care center in her public-housing apartment got the shock of her life when the IRS slapped her with a $6 million-plus lien for unpaid income taxes.

City records show the IRS filed the massive bill with the city Department of Finance on July 31 against Mariana Conforme, a 64-year-old Ecuadorian immigrant who lives in the Jefferson Houses.

The lien lists eight years of unpaid assessments on her Form 1040 tax returns, ranging from $1,126 to more than $6 million.

Conforme told The Post that she got a letter from the IRS last month but “couldn’t understand it because it’s in English.”

When told that the bottom line was a bill for nearly $6.1 million, she couldn’t believe her ears.

“It’s true that I haven’t paid everything, but not for it to be this quantity, not for it to be 6 million,” she said in Spanish.

The city Administration for Children’s Services said Conforme is one of about 9,200 people it pays to care for the children of low-income parents. The city doesn’t withhold and pay any of their income taxes but reports their annual earnings to the IRS on a Form 1099. Conforme was paid $17,497 last year, ACS said.

Conforme has a state license to operate a day-care center for up to six kids in her two-bedroom apartment, for which she said she pays $500 a month, but she’s now caring for two.

“I am poor, I am basically living paycheck to paycheck,” Conforme lamented. “I probably won’t make $1 million in 20 years of doing this.”

After learning about her alarming debt, Conforme contacted the IRS on Thursday and said she was told it was all a mistake.

“They said I only owe $2,000 and will be sending me a new letter next week,” she said. An IRS spokesperson wouldn’t discuss the matter, citing privacy rules.

Additional reporting by Bruce Golding