Under section 469 of the Taxes Consolidation Act, 1997, tax relief is available in respect of certain non-routine unreimbursable health expenses incurred in a tax year. The first £100 of health expenses in the case of a single person, or £200 in the case of a married couple or family, are excluded from the scope of the relief. The cost of orthodontic treatment is a health expense for the purposes of section 469. The treatment must be carried out by a dentist who is registered in the register established under section 26 of the Dentists Act, 1985; or if the orthodontic treatment is provided outside the State, by a dentist who is entitled under the laws of the country where the treatment is carried out to practise dentistry there. The relief, which is allowed at the taxpayer's marginal rate of tax, can be claimed on a MED 1 form which must be accompanied by a MED 2 form completed by the dentist who carried out the treatment.