An appellate court has upheld Ronald Isley's 37-month federal prison sentence for tax evasion.

The three-judge panel rejected the 66-year-old R&B singer's argument that his sentence was unreasonable due to his age, poor health and lack of proof that the federal prison system can provide him adequate health care.

In its ruling, the appellate court said the trial judge was correct in sentencing and "best balanced the need to sanction Mr. Isley's `pathological' tax evasion against the need to accommodate Mr. Isley's poor health."

Isley was sentenced in 2006 after being convicted of five counts of tax evasion and one count of willful failure to file a tax return.

Prosecutors said Isley avoided paying taxes numerous times over a three-year period and declared bankruptcy after the IRS seized his yacht, cars and other property in 1997.

He was discharged from bankruptcy four years later, but then did not file tax returns for the years 1997 to 2001 and in 2002 did not sign his return and failed to pay all taxes due.

Isley suffered a minor stroke in July 2004, but got married one year later and continuously performed concerts at that time. He is incarcerated at the Terre Haute Federal Corrections Institution in Indiana and his projected release date is in April 2010.

Isley was inducted into the Rock and Roll Hall of Fame and was part of the Isley Brothers, whose hits included "Twist and Shout" and "This Old Heart of Mine (Is Weak for You)."