Is this a pension...it sounds more like an Annuity?
If an Annuity, you may want to check on something called Medical Underwriting.
From the Vanguard website:
Medical Underwriting
"Clients with medical conditions that may reduce their life expectancy may qualify for a “rated age”. A rated age is older than your actual age and based on your personal life expectancy as determined by a medical underwriter. A rated age applicant can either increase their income payments or reduce the premium amount needed to generate specific payment amounts.
If you choose to apply for a rated age, you can NOT lock in a quote with a rated age until the medical underwriting process is completed. Applying for a rated age will delay the time it takes to lock in a quote. For more information on Medical Underwriting, call 800-522-5555, Monday through Friday, 8 a.m. to 8 p.m., Eastern Time."