Ackerman was initially banned in October last year after being found guilty of corruption.
He had laid bets against a horse knowing its jockey aimed not to win.
Ackerman was granted a stay of implementation in November, but his disqualification has been reactivated with immediate effect until 11 June.
However, his fine of £5,000 was quashed upon appeal, at the invitation of the British Horseracing Authority.
Ackerman was banned after an investigation into six races featuring Ad Vitam at Kempton and Wolverhampton between 2 November, 2011 and 8 March, 2012.
He was found to have breached the rules of racing alongside jockey Michael Stainton, registered owner Kenneth Mackay and former owner David Greenwood.
Stainton was banned for two years, Mackay for six months and fined £5,000, with Greenwood, who had already been warned off for a separate offence, banned for eight years. All three also failed in their appeals, although, a separate appeal by Stainton against the penalty imposed "will be considered in due course".
Stewart-Moore Solicitors, who represent Ackerman, Greenwood and Mackay, said in a statement that the "matter needs to be resolved by a High Court judge".
"Messrs Ackerman, Greenwood and Mackay have not acted in breach of the rules of racing in any way," they added.
"In spite of this they have been found, yet again, to have taken part in a conspiracy that has never been properly put to them."

We received that question from Drew who is planning a trip to New York in December. He asked: "Should I get my cash now or should I wait? Will there be much change between now and then?"
Anthony Reuben, from BBC Reality Check, had this answer: "The BBC does not give financial advice, but here are a few things to bear in mind...
"The exchange rate between the pound and the dollar reflects the views of investors about the relative strengths of the two economies.
"Since the Brexit vote in June the pound has fallen about 18% against the dollar on the judgment that growth is likely to be stronger in the US than the UK and that UK interest rates are falling while the next movement in US rates is expected to be upwards.
"But it's always possible that something could happen to change that view - there is a presidential election in the US in November, for example. The outcome of that could make a considerable difference to the exchange rate.
"You do not necessarily have to put all your eggs in one basket - there is also the option to hedge your bets and buy half of your dollars now and half of them just before you go, as long as you are not going to be hit by extra charges for carrying out two transactions.
"It is always worth shopping around when buying currency - avoid buying your currency at the last minute at the airport. There are plenty of comparison sites online that will help you get the most dollars possible for your pounds, even if it is fewer than you would have got a few months ago."
We asked readers to send in questions about the recent fall of the pound and rise of the FTSE 100.
Anthony chose Drew's question: "I'm planning on going to New York in December, should I get my cash now or wait? Will there be much change between now and then?"
Take a look at some of the other questions you've wanted us to answer:
Why does the NHS spend on homeopathy?
Could the UK take over existing EU trade deals?
Does fracking affect the water supply?
If you are reading this page on the BBC News app, you will need to visit the mobile version of the BBC website to submit your question.
Towcester racecourse chief executive Kevin Ackerman has failed in his bid to overturn a six-month suspension from racing.
[NEXT_CONCEPT]
With the value of the pound falling dramatically since Brexit, a "flash crash" last week when the currency lost 6% of its value against the dollar, and news on Tuesday that the pound had fallen again, when would be a good time to change those pounds to dollars?