Almost 50,000 medical cards have been withdrawn from patients so far this year following a review.
The Health Service Executive (HSE) cancelled 9,891 cards of people it said were no longer eligible and 35,733 from people who did not respond to requests for more information.
Health Minister James Reilly rejected claims of a slowdown in the number of new cards being issued in a bid to meet targets and growing budget cuts.
Launching a publicity drive to explain tightening of eligibility rules, he admitted patients had been left confused in recent weeks and apologised for any distress caused.
"Nobody who is entitled to a medical card will lose it or be refused one," Dr Reilly said.
Approximately 1.86 million people have a full medical card as well as 123,424 with a GP only card.
However, thousands of elderly, disabled and chronically ill people fear they will lose their full entitlements as the embattled minister attempts to cut 113 million euro from the medical card bill.
New figures revealed 428,000 reviews of card holders have been carried out so far this year, compared with 365,200 last year.
Cards were withdrawn from:
:: 9,891 people who were no longer eligible.
:: 3,992 who were deceased.
:: 35,733 who did not respond to HSE letters or provide sufficient information to review their application.
:: The HSE had already confirmed 17,059 discretionary cards were withdrawn between March 2011 and October 2013, of which 2,361 of the cardholders had died.
Patrick Burke, head of the HSE's medical card scheme, denied cards were being withheld on a budgetary basis, stressing 106,000 new cards had been issued so far this year, including renewals.
"Every single application that comes in to us is assessed against what are the national guidelines," he said.
"There is no policy, there is no instruction, there is nothing to not allow any application that comes to us to be assessed.
"The question of how the HSE delivers its national services with a budget to be set for 2014 is something that will be worked out through the service plan."
Any application above the income threshold is examined by a team of doctors to assess if the patient should be given free healthcare based on their medical condition, including "two or three" cases highlighted in the media in recent weeks, he added.
A card is also given to those who are terminally ill and deemed to have six months to live.
The Budget medical card crackdown plans to take the free healthcare off the unemployed immediately after they find work, and move from automatic entitlement to medical cards to an income threshold for over-70s.
Charities warned about 35,000 pensioners are expected to lose their cards, while hundreds of other concerned patients and parents have flooded radio shows since the budget with complaints that they have already lost their full entitlements as eligibility policies are enforced.
The HSE launched a 150,000 euro public relations drive after the minister accepted his department and the HSE had to take responsibility for the lack of clarity and information involved in the scheme.
Information is available on who is eligible for a medical card via www.medicalcard.ie, in new booklets, adverts in national newspapers and on upgraded information helplines.
Support groups like Age Action and Down Syndrome Ireland will also be updated.
But medics criticised the HSE's new PR campaign and accused it of spin.
Dr Ray Walley, chairman of the GP committee of the Irish Medical Organisation, said: "How can you explain that nothing has changed to an elderly patient who is losing the card she is dependent upon."