Sec 80ddb deduction

Deduction under section 80DDB can be claimed only by the person incurring the expenses. However, the medical expenses can be incurred for the treatment of the following people:

• Individuals: In case of an individual, the medical expense can be incurred on the medical treatment of the assessee or any of his dependents. The ‘dependents’ in respect of this section would include spouse, his children, his parents, brothers and sisters of the individual or any of them. The dependent as the world suggests should be ‘dependent on the individual’ for his or her maintenance and support.
• Hindu Undivided Family (HUF): In case of an HUF, the medical expense can be claimed as deduction wherein the same are incurred for medical treatment of any member of the HUF.

Following diseases specified under rule 11DD qualify for tax deduction u/s 80DDB. 

• Neurological diseases where the disability level has been certified (prescriptttion issued by Neurologist having ‘Doctorate of Medicine’ degree or equivalent qualification) to be of 40% and above:
  1. Dementia
  2. Dystonia Musculorum Deformans
  3. Motor Neuron Disease
  4. Ataxia
  5. Chorea
  6. Hemiballismus
  7. Aphasia
  8. Parkinsons Disease
• Malignant Cancers (prescriptttion issued by Oncologist having Doctorate of Medicine degree or equivalent qualification)
• Full Blown Acquired Immuno-Deficiency Syndrome (AIDS) (prescriptttion issued by any specialist having a post-graduate degree in General or Internal Medicine or equivalent qualification)
• Chronic renal failure (prescriptttion issued by a Nephrologist / Urologist having Doctorate of Medicine degree or equivalent qualification)
• Hematological disorders (prescriptttion issued by a Hematologist having Doctorate of Medicine degree or equivalent qualification):
  1. Hemophilia
  2. Thalassaemia

There is no connection between pension income and deduction u/s. 80DDB.

Father can have his pension assessed separately, and son can claim the deduction u/s. 80DDB for any expenses incurred for treatment of any the specified disease for himself or dependent father, independently.