Complying with the requirements of the Disability Discrimination Act could cost the NHS up to£100m a year for the next five years, according to a report commissioned by the NHS Executive.
From October, providers must take 'reasonable steps' to change practices, policies and procedures that make it impossible or 'unreasonably difficult' for disabled people to get access to services.
From 2004, they must take reasonable steps to remove or alter physical features that prevent access.
A report from specialist company Disability Matters says removing all physical barriers by that date would cost 'in the region of£540m'.
But it says the figure could be roughly halved - to£271.5m - if disability issues are automatically dealt with in planned programmes of work, policies are reviewed and staff are given better training.
In guidance issued with the report, health services director Dr Sheila Adam says 'statutory compliance with the act has been identified as a priority for capital investment and will be targeted in future capital allocations'.
Neil Betteridge, head of projects and campaigns for the Royal Association for Disability and Rehabilitation, said access to NHS facilities, and GP premises in particular, was 'awful'.
He recognised that considerable concern had been expressed about the cost of complying with the act, but said the requirement to take 'reasonable' steps was designed to protect organisations from incurring excessive costs. 'Our argument has always been with the timescale,' he said.
'If people only have to take reasonable steps, they should take them now.'
But Andy Collingwood, chair of the Health Facilities Management Association, said: 'I am sure this is the right thing to do, but it has to be done in the context of all the other pressures being placed on the health service and other organisations.'
Andrew Foster, NHS Confederation chair of human resources and chair of Wigan and Leigh Health Services trust, said: 'As a trust, this is a major problem for us.
'There is nothing wrong with the act - we would all sign up to it. But it is another huge, huge unfunded pressure on the NHS.'
Jean Sapeta, a partner at solicitors Bevan Ashford specialising in NHS issues, said the health service was 'not likely to be viewed very sympathetically in any proceedings' and would not be able to 'hide behind' arguments that money was tight.
The guidance says hospitals and other NHS organisations should start auditing physical access to premises, making toilet facilities 'a particular priority'.
Gerda Loosemore-Reppen, policy and resources officer for the Royal National Institute for Deaf People, welcomed the 'tone' of the report and the approach taken by the Executive. She said many access problems required common sense, rather than high-tech solutions.
Implementing Section 21 of the Disability Discrimination Act 1995 Across the NHS. http://tap.ccta.gov.uk/doh/ coin4.nsf