The HSE has written a letter of apology to the husband of Ruth Morrissey.
The funeral of the 39-year-old CervicalCheck campaigner is taking place today.
Following her passing on Sunday, her husband Paul criticised the State and the HSE for not apologising to Ruth despite the harm caused to her by "avoidable errors".
A statement issued on behalf of Mr Morrissey said: "Despite the magnitude of the harm caused to her by avoidable errors, despite the broken promise of a Taoiseach who said no other woman would have to go to trial, despite using Ruth as a test case through the final years and months of her life, neither the HSE nor the State has ever apologised to her, and now it is too late."
HSE Chief Executive Paul Reid this morning expressed his "heartfelt sympathies" to Ruth's family.
He said: "I am very conscious that very shortly the funeral will take place of Ruth Morrissey - it's a very sad day for her husband Paul, her daughter Libby and their family.
"Ruth was an incredibly courageous woman.
"I appreciate today isn't the time for me to say much more on this... but I want to mention I have written to Paul Morrissey through their solicitor to offer an apology on behalf of the HSE, and express my deepest sympathies and apologies for what has happened to Ruth."
Ms Morrissey, who had cervical cancer, passed away peacefully at Milford Hospice.
She had been awarded €2.1m by the High Court in 2019 over the misreading of her smear test results.